Use nullptr

69 files changed, 443 insertions, 511 deletions

diff --git a/paludis/repositories/accounts/accounts_id.cc b/paludis/repositories/accounts/accounts_id.cc
index ff985c19c..dd94cd1e6 100644
--- a/paludis/repositories/accounts/accounts_id.cc
+++ b/paludis/repositories/accounts/accounts_id.cc
@@ -29,7 +29,6 @@
 #include <paludis/util/tokeniser.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/wrapped_output_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/output_manager.hh>
@@ -108,7 +107,7 @@ namespace paludis
             fs_location_key(std::make_shared<LiteralMetadataValueKey<FSPath>>("location", "Location", mkt_internal, l)),
             from_repositories_key(f),
             behaviours_key(AccountsIDBehaviours::get_instance()->behaviours_key),
-            mask(m ? std::make_shared<AccountsInstalledMask>() : make_null_shared_ptr()),
+            mask(m ? std::make_shared<AccountsInstalledMask>() : nullptr),
             is_user(u),
             has_file_keys(false),
             has_metadata_keys(false)
@@ -313,7 +312,7 @@ AccountsID::uniquely_identifying_spec() const
 const std::shared_ptr<const MetadataCollectionKey<KeywordNameSet> >
 AccountsID::keywords_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
@@ -333,7 +332,7 @@ AccountsID::run_dependencies_key() const
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
 AccountsID::post_dependencies_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
@@ -346,13 +345,13 @@ AccountsID::dependencies_key() const
 const std::shared_ptr<const MetadataSpecTreeKey<FetchableURISpecTree> >
 AccountsID::fetches_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<SimpleURISpecTree> >
 AccountsID::homepage_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::string> >
@@ -370,13 +369,13 @@ AccountsID::short_description_key() const
 const std::shared_ptr<const MetadataValueKey<std::string> >
 AccountsID::long_description_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataTimeKey>
 AccountsID::installed_time_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
@@ -400,13 +399,13 @@ AccountsID::behaviours_key() const
 const std::shared_ptr<const MetadataValueKey<std::shared_ptr<const Choices> > >
 AccountsID::choices_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<Slot> >
 AccountsID::slot_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 std::shared_ptr<const Set<std::string> >
@@ -479,7 +478,7 @@ AccountsID::perform_action(Action & action) const
                 n::options() = MergerOptions() + mo_rewrite_symlinks + mo_allow_empty_dirs,
                 n::output_manager() = output_manager,
                 n::package_id() = shared_from_this(),
-                n::parts() = make_null_shared_ptr(),
+                n::parts() = nullptr,
                 n::perform_uninstall() = install_action->options.perform_uninstall(),
                 n::permit_destination() = std::bind(return_literal_function(true)),
                 n::replacing() = install_action->options.replacing(),
@@ -542,7 +541,7 @@ AccountsID::perform_action(Action & action) const
                         n::ignore_for_unmerge() = &ignore_nothing,
                         n::is_overwrite() = false,
                         n::make_output_manager() = std::bind(&this_output_manager, output_manager, std::placeholders::_1),
-                        n::override_contents() = make_null_shared_ptr(),
+                        n::override_contents() = nullptr,
                         n::want_phase() = install_action->options.want_phase()
                         ));
             install_action->options.perform_uninstall()(*i, uo);
@@ -555,6 +554,6 @@ AccountsID::perform_action(Action & action) const
 const std::shared_ptr<const Contents>
 AccountsID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/accounts/accounts_repository.cc b/paludis/repositories/accounts/accounts_repository.cc
index ea00958cc..91aeff753 100644
--- a/paludis/repositories/accounts/accounts_repository.cc
+++ b/paludis/repositories/accounts/accounts_repository.cc
@@ -1,7 +1,7 @@
 /* vim: set sw=4 sts=4 et foldmethod=syntax : */
 
 /*
- * Copyright (c) 2009, 2010, 2011 Ciaran McCreesh
+ * Copyright (c) 2009, 2010, 2011, 2013 Ciaran McCreesh
  *
  * This file is part of the Paludis package manager. Paludis is free software;
  * you can redistribute it and/or modify it under the terms of the GNU General
@@ -29,7 +29,6 @@
 #include <paludis/util/deferred_construction_ptr.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/log.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/literal_metadata_key.hh>
 #include <paludis/action.hh>
 #include <paludis/package_id.hh>
@@ -247,7 +246,7 @@ AccountsRepository::format_key() const
 const std::shared_ptr<const MetadataValueKey<FSPath> >
 AccountsRepository::location_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<FSPath> >
@@ -259,7 +258,7 @@ AccountsRepository::installed_root_key() const
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 AccountsRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 void
@@ -444,7 +443,7 @@ AccountsRepository::sync(
 const std::shared_ptr<const Set<std::string> >
 AccountsRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/accounts/installed_accounts_id.cc b/paludis/repositories/accounts/installed_accounts_id.cc
index f0babf6fb..4bba75464 100644
--- a/paludis/repositories/accounts/installed_accounts_id.cc
+++ b/paludis/repositories/accounts/installed_accounts_id.cc
@@ -28,7 +28,6 @@
 #include <paludis/util/tokeniser.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/log.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/name.hh>
 #include <paludis/version_spec.hh>
@@ -229,13 +228,13 @@ InstalledAccountsID::uniquely_identifying_spec() const
 const std::shared_ptr<const MetadataCollectionKey<KeywordNameSet> >
 InstalledAccountsID::keywords_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
 InstalledAccountsID::build_dependencies_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
@@ -248,7 +247,7 @@ InstalledAccountsID::run_dependencies_key() const
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
 InstalledAccountsID::post_dependencies_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
@@ -261,43 +260,43 @@ InstalledAccountsID::dependencies_key() const
 const std::shared_ptr<const MetadataSpecTreeKey<FetchableURISpecTree> >
 InstalledAccountsID::fetches_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<SimpleURISpecTree> >
 InstalledAccountsID::homepage_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::string> >
 InstalledAccountsID::short_description_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::string> >
 InstalledAccountsID::long_description_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataTimeKey>
 InstalledAccountsID::installed_time_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 InstalledAccountsID::from_repositories_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<FSPath> >
 InstalledAccountsID::fs_location_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
@@ -309,13 +308,13 @@ InstalledAccountsID::behaviours_key() const
 const std::shared_ptr<const MetadataValueKey<std::shared_ptr<const Choices> > >
 InstalledAccountsID::choices_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<Slot> >
 InstalledAccountsID::slot_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 std::shared_ptr<const Set<std::string> >
@@ -351,6 +350,6 @@ InstalledAccountsID::perform_action(Action & action) const
 const std::shared_ptr<const Contents>
 InstalledAccountsID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/e/dep_parser.cc b/paludis/repositories/e/dep_parser.cc
index 66650eeaa..140f4dfbc 100644
--- a/paludis/repositories/e/dep_parser.cc
+++ b/paludis/repositories/e/dep_parser.cc
@@ -32,7 +32,6 @@
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/visitor_cast.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/elike_dep_parser.hh>
 #include <paludis/elike_conditional_dep_spec.hh>
diff --git a/paludis/repositories/e/do_fetch_action.cc b/paludis/repositories/e/do_fetch_action.cc
index ae47d70f3..6e5dd94c7 100644
--- a/paludis/repositories/e/do_fetch_action.cc
+++ b/paludis/repositories/e/do_fetch_action.cc
@@ -36,7 +36,6 @@
 #include <paludis/util/wrapped_output_iterator.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/join.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/dep_spec_flattener.hh>
 #include <paludis/metadata_key.hh>
@@ -195,8 +194,8 @@ paludis::erepository::do_fetch_action(
                         n::maybe_output_manager() = output_manager,
                         n::package_builddir() = package_builddir,
                         n::package_id() = id,
-                        n::parts() = make_null_shared_ptr(),
-                        n::permitted_directories() = make_null_shared_ptr(),
+                        n::parts() = nullptr,
+                        n::permitted_directories() = nullptr,
                         n::portdir() =
                             (params.master_repositories() && ! params.master_repositories()->empty())
                                 ? (*params.master_repositories()->begin())->params().location()
@@ -245,8 +244,8 @@ paludis::erepository::do_fetch_action(
                         n::maybe_output_manager() = output_manager,
                         n::package_builddir() = repo->params().builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-nofetch"),
                         n::package_id() = id,
-                        n::parts() = make_null_shared_ptr(),
-                        n::permitted_directories() = make_null_shared_ptr(),
+                        n::parts() = nullptr,
+                        n::permitted_directories() = nullptr,
                         n::portdir() = (repo->params().master_repositories() && ! repo->params().master_repositories()->empty()) ?
                             (*repo->params().master_repositories()->begin())->params().location() : repo->params().location(),
                         n::root() = "/",
diff --git a/paludis/repositories/e/do_info_action.cc b/paludis/repositories/e/do_info_action.cc
index ed02f7aa8..117a261d5 100644
--- a/paludis/repositories/e/do_info_action.cc
+++ b/paludis/repositories/e/do_info_action.cc
@@ -28,7 +28,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/join.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/dep_spec_flattener.hh>
 #include <paludis/action.hh>
@@ -104,8 +103,8 @@ paludis::erepository::do_info_action(
                 n::maybe_output_manager() = output_manager,
                 n::package_builddir() = params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-info"),
                 n::package_id() = id,
-                n::parts() = make_null_shared_ptr(),
-                n::permitted_directories() = make_null_shared_ptr(),
+                n::parts() = nullptr,
+                n::permitted_directories() = nullptr,
                 n::portdir() =
                     (params.master_repositories() && ! params.master_repositories()->empty())
                         ? (*params.master_repositories()->begin())->params().location()
diff --git a/paludis/repositories/e/do_install_action.cc b/paludis/repositories/e/do_install_action.cc
index f1a3afb0f..7dfe759dc 100644
--- a/paludis/repositories/e/do_install_action.cc
+++ b/paludis/repositories/e/do_install_action.cc
@@ -38,7 +38,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/join.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/util/tokeniser.hh>
 
@@ -507,7 +506,7 @@ paludis::erepository::do_install_action(
                             std::placeholders::_1),
                         n::is_overwrite() = false,
                         n::make_output_manager() = std::bind(&this_output_manager, output_manager, std::placeholders::_1),
-                        n::override_contents() = make_null_shared_ptr(),
+                        n::override_contents() = nullptr,
                         n::want_phase() = install_action.options.want_phase()
                         ));
             install_action.options.perform_uninstall()(*i, uo);
diff --git a/paludis/repositories/e/do_pretend_action.cc b/paludis/repositories/e/do_pretend_action.cc
index 6806e1f72..60cd04953 100644
--- a/paludis/repositories/e/do_pretend_action.cc
+++ b/paludis/repositories/e/do_pretend_action.cc
@@ -31,7 +31,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/join.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/dep_spec_flattener.hh>
 #include <paludis/metadata_key.hh>
@@ -121,8 +120,8 @@ paludis::erepository::do_pretend_action(
                             n::maybe_output_manager() = output_manager,
                             n::package_builddir() = params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-bad_options"),
                             n::package_id() = id,
-                            n::parts() = make_null_shared_ptr(),
-                            n::permitted_directories() = make_null_shared_ptr(),
+                            n::parts() = nullptr,
+                            n::permitted_directories() = nullptr,
                             n::portdir() =
                                 (params.master_repositories() && ! params.master_repositories()->empty()) ?
                                 (*params.master_repositories()->begin())->params().location() : params.location(),
@@ -187,8 +186,8 @@ paludis::erepository::do_pretend_action(
                             n::maybe_output_manager() = output_manager,
                             n::package_builddir() = params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-bad_options"),
                             n::package_id() = id,
-                            n::parts() = make_null_shared_ptr(),
-                            n::permitted_directories() = make_null_shared_ptr(),
+                            n::parts() = nullptr,
+                            n::permitted_directories() = nullptr,
                             n::portdir() =
                                 (params.master_repositories() && ! params.master_repositories()->empty())
                                     ? (*params.master_repositories()->begin())->params().location()
@@ -252,8 +251,8 @@ paludis::erepository::do_pretend_action(
                 n::maybe_output_manager() = output_manager,
                 n::package_builddir() = params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-pretend"),
                 n::package_id() = id,
-                n::parts() = make_null_shared_ptr(),
-                n::permitted_directories() = make_null_shared_ptr(),
+                n::parts() = nullptr,
+                n::permitted_directories() = nullptr,
                 n::portdir() =
                     (params.master_repositories() && ! params.master_repositories()->empty())
                         ? (*params.master_repositories()->begin())->params().location()
diff --git a/paludis/repositories/e/e_choice_value.cc b/paludis/repositories/e/e_choice_value.cc
index e381ac3ce..342e10daf 100644
--- a/paludis/repositories/e/e_choice_value.cc
+++ b/paludis/repositories/e/e_choice_value.cc
@@ -19,7 +19,6 @@
 
 #include <paludis/repositories/e/e_choice_value.hh>
 #include <paludis/repositories/e/use_desc.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/pimp-impl.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/pool-impl.hh>
@@ -107,7 +106,7 @@ EChoiceValue::parameter() const
 const std::shared_ptr<const PermittedChoiceValueParameterValues>
 EChoiceValue::permitted_parameter_values() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 bool
diff --git a/paludis/repositories/e/e_installed_repository.cc b/paludis/repositories/e/e_installed_repository.cc
index 2632c1951..a94e1bdec 100644
--- a/paludis/repositories/e/e_installed_repository.cc
+++ b/paludis/repositories/e/e_installed_repository.cc
@@ -41,7 +41,6 @@
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/join.hh>
 #include <paludis/util/is_file_with_extension.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/action.hh>
 #include <paludis/package_id.hh>
@@ -266,8 +265,8 @@ EInstalledRepository::perform_config(
                     n::maybe_output_manager() = output_manager,
                     n::package_builddir() = _imp->params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-config"),
                     n::package_id() = id,
-                    n::parts() = make_null_shared_ptr(),
-                    n::permitted_directories() = make_null_shared_ptr(),
+                    n::parts() = nullptr,
+                    n::permitted_directories() = nullptr,
                     n::portdir() = ver_dir,
                     n::root() = stringify(_imp->params.root()),
                     n::sandbox() = phase->option("sandbox"),
@@ -375,8 +374,8 @@ EInstalledRepository::perform_info(
                     n::maybe_output_manager() = output_manager,
                     n::package_builddir() = _imp->params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-info"),
                     n::package_id() = id,
-                    n::parts() = make_null_shared_ptr(),
-                    n::permitted_directories() = make_null_shared_ptr(),
+                    n::parts() = nullptr,
+                    n::permitted_directories() = nullptr,
                     n::portdir() = ver_dir,
                     n::root() = stringify(_imp->params.root()),
                     n::sandbox() = phase->option("sandbox"),
@@ -417,6 +416,6 @@ EInstalledRepository::sync(const std::string &, const std::string &, const std::
 const std::shared_ptr<const Set<std::string> >
 EInstalledRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/e/e_installed_repository_id.cc b/paludis/repositories/e/e_installed_repository_id.cc
index 8a2f9fd02..a66dcbd26 100644
--- a/paludis/repositories/e/e_installed_repository_id.cc
+++ b/paludis/repositories/e/e_installed_repository_id.cc
@@ -36,7 +36,6 @@
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/return_literal_function.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/strip.hh>
@@ -515,10 +514,10 @@ EInstalledRepositoryID::need_keys_added() const
     if (_imp->eapi->supported())
         _imp->keys->choices = std::make_shared<EChoicesKey>(_imp->environment, shared_from_this(), "PALUDIS_CHOICES",
                     _imp->eapi->supported()->ebuild_environment_variables()->description_choices(),
-                    mkt_normal, make_null_shared_ptr(), std::bind(return_literal_function(make_null_shared_ptr())));
+                    mkt_normal, nullptr, std::bind(return_literal_function(nullptr)));
     else
         _imp->keys->choices = std::make_shared<EChoicesKey>(_imp->environment, shared_from_this(), "PALUDIS_CHOICES", "Choices", mkt_normal,
-                    make_null_shared_ptr(), std::bind(return_literal_function(make_null_shared_ptr())));
+                    nullptr, std::bind(return_literal_function(nullptr)));
 
     add_metadata_key(_imp->keys->choices);
 
@@ -763,7 +762,7 @@ EInstalledRepositoryID::license_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 EInstalledRepositoryID::behaviours_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
diff --git a/paludis/repositories/e/e_repository.cc b/paludis/repositories/e/e_repository.cc
index ba0e2a7ed..63a914169 100644
--- a/paludis/repositories/e/e_repository.cc
+++ b/paludis/repositories/e/e_repository.cc
@@ -79,7 +79,6 @@
 #include <paludis/util/join.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/make_shared_copy.hh>
 #include <paludis/util/map.hh>
 #include <paludis/util/options.hh>
@@ -1745,11 +1744,11 @@ ERepository::get_environment_variable(
             n::environment() = _imp->params.environment(),
             n::exlibsdirs() = exlibsdirs,
             n::files_dir() = layout()->package_directory(id->name()) / "files",
-            n::maybe_output_manager() = make_null_shared_ptr(),
+            n::maybe_output_manager() = nullptr,
             n::package_builddir() = _imp->params.builddir() / (stringify(id->name().category()) + "-" + stringify(id->name().package()) + "-" + stringify(id->version()) + "-variable"),
             n::package_id() = id,
-            n::parts() = make_null_shared_ptr(),
-            n::permitted_directories() = make_null_shared_ptr(),
+            n::parts() = nullptr,
+            n::permitted_directories() = nullptr,
             n::portdir() =
                 (_imp->params.master_repositories() && ! _imp->params.master_repositories()->empty()) ?
                 (*_imp->params.master_repositories()->begin())->params().location() : _imp->params.location(),
@@ -1776,7 +1775,7 @@ namespace
                 i != i_end ; ++i)
             if ((*i)->version() == v)
                 return *i;
-        return make_null_shared_ptr();
+        return nullptr;
     }
 }
 
diff --git a/paludis/repositories/e/e_repository_TEST.cc b/paludis/repositories/e/e_repository_TEST.cc
index 3de7415a4..b450ff58e 100644
--- a/paludis/repositories/e/e_repository_TEST.cc
+++ b/paludis/repositories/e/e_repository_TEST.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/fs_stat.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -408,7 +407,7 @@ TEST(ERepository, MetadataUncached)
         {
             const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-1",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
 
             EXPECT_TRUE(id1->end_metadata() != id1->find_metadata("EAPI"));
             EXPECT_TRUE(visitor_cast<const MetadataValueKey<std::string> >(**id1->find_metadata("EAPI")));
@@ -427,7 +426,7 @@ TEST(ERepository, MetadataUncached)
 
             const std::shared_ptr<const PackageID> id2(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-2",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
 
             ASSERT_TRUE(id2->end_metadata() != id2->find_metadata("EAPI"));
             ASSERT_TRUE(bool(id2->short_description_key()));
@@ -443,7 +442,7 @@ TEST(ERepository, MetadataUncached)
 
             const std::shared_ptr<const PackageID> id3(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-3",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
 
             ASSERT_TRUE(id3->end_metadata() != id3->find_metadata("EAPI"));
             ASSERT_TRUE(bool(id3->short_description_key()));
@@ -471,7 +470,7 @@ TEST(ERepository, MetadataUnparsable)
     {
         const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-two-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
 
         ASSERT_TRUE(id1->end_metadata() != id1->find_metadata("EAPI"));
         EXPECT_EQ("UNKNOWN", std::static_pointer_cast<const erepository::ERepositoryID>(id1)->eapi()->name());
@@ -513,13 +512,13 @@ TEST_F(ERepositoryQueryUseTest, QueryUse)
     {
         const std::shared_ptr<const PackageID> p1(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         const std::shared_ptr<const PackageID> p2(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat-two/pkg-two-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         const std::shared_ptr<const PackageID> p4(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
 
         test_choice(p1, "flag1",     true,  true,  false);
         test_choice(p1, "flag2",     false, false, true);
@@ -589,19 +588,19 @@ TEST_F(ERepositoryQueryUseTest, UseStableMaskForce)
         {
             const std::shared_ptr<const PackageID> stable1(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/stable-1",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
             const std::shared_ptr<const PackageID> stable1r1(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/stable-1-r1",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
             const std::shared_ptr<const PackageID> stable2(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/stable-2",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
             const std::shared_ptr<const PackageID> unstable1(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/unstable-1",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
             const std::shared_ptr<const PackageID> missing1(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/missing-1",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                    &env, { })), nullptr, { }))]->begin());
 
             test_choice(stable1, "notstmask",     false, false, false);
             test_choice(stable1, "notpkgstmask",  false, false, false);
@@ -795,29 +794,29 @@ TEST(ERepository, Masks)
 
     EXPECT_TRUE((*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-1::test-repo-18",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
     EXPECT_TRUE((*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-2::test-repo-18",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
     EXPECT_TRUE(! (*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-3::test-repo-18",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
     EXPECT_TRUE(! (*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-4::test-repo-18",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
 
     EXPECT_TRUE((*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-1::test-repo-19",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
     EXPECT_TRUE(! (*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-2::test-repo-19",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
     EXPECT_TRUE((*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-3::test-repo-19",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
     EXPECT_TRUE(! (*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=category/package-4::test-repo-19",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                &env, { })), nullptr, { }))]->begin())->masked());
 }
 
 TEST(ERepository, ProfileMasks)
@@ -837,13 +836,13 @@ TEST(ERepository, ProfileMasks)
     {
         EXPECT_TRUE((*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/masked-0",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                    &env, { })), nullptr, { }))]->begin())->masked());
         EXPECT_TRUE(! (*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/was_masked-0",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                    &env, { })), nullptr, { }))]->begin())->masked());
         EXPECT_TRUE(! (*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/not_masked-0",
-                                    &env, { })), make_null_shared_ptr(), { }))]->begin())->masked());
+                                    &env, { })), nullptr, { }))]->begin())->masked());
     }
 }
 
@@ -928,7 +927,7 @@ TEST(ERepository, Fetch)
     {
         const std::shared_ptr<const PackageID> no_files_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/no-files",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(no_files_id));
         ASSERT_TRUE(bool(no_files_id->short_description_key()));
         EXPECT_EQ("The Short Description", no_files_id->short_description_key()->parse_value());
@@ -938,7 +937,7 @@ TEST(ERepository, Fetch)
     {
         const std::shared_ptr<const PackageID> fetched_files_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/fetched-files",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(fetched_files_id));
         EXPECT_TRUE((FSPath("e_repository_TEST_dir") / "distdir" / "already-fetched.txt").stat().is_regular_file());
         fetched_files_id->perform_action(action);
@@ -949,7 +948,7 @@ TEST(ERepository, Fetch)
         EXPECT_TRUE(! (FSPath("e_repository_TEST_dir") / "distdir" / "fetchable-1.txt").stat().is_regular_file());
         const std::shared_ptr<const PackageID> fetchable_files_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/fetchable-files",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(fetchable_files_id));
         fetchable_files_id->perform_action(action);
         EXPECT_TRUE((FSPath("e_repository_TEST_dir") / "distdir" / "fetchable-1.txt").stat().is_regular_file());
@@ -959,7 +958,7 @@ TEST(ERepository, Fetch)
         EXPECT_TRUE(! (FSPath("e_repository_TEST_dir") / "distdir" / "arrowed.txt").stat().is_regular_file());
         const std::shared_ptr<const PackageID> arrow_files_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/arrow-files",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(arrow_files_id));
         arrow_files_id->perform_action(action);
         EXPECT_TRUE((FSPath("e_repository_TEST_dir") / "distdir" / "arrowed.txt").stat().is_regular_file());
@@ -968,7 +967,7 @@ TEST(ERepository, Fetch)
     {
         const std::shared_ptr<const PackageID> unfetchable_files_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/unfetchable-files",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(unfetchable_files_id));
         EXPECT_THROW(unfetchable_files_id->perform_action(action), ActionFailedError);
     }
@@ -976,7 +975,7 @@ TEST(ERepository, Fetch)
     {
         const std::shared_ptr<const PackageID> no_files_restricted_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/no-files-restricted",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(no_files_restricted_id));
         no_files_restricted_id->perform_action(action);
     }
@@ -984,7 +983,7 @@ TEST(ERepository, Fetch)
     {
         const std::shared_ptr<const PackageID> fetched_files_restricted_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/fetched-files-restricted",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(fetched_files_restricted_id));
         fetched_files_restricted_id->perform_action(action);
     }
@@ -992,7 +991,7 @@ TEST(ERepository, Fetch)
     {
         const std::shared_ptr<const PackageID> fetchable_files_restricted_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/fetchable-files-restricted",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(fetchable_files_restricted_id));
         EXPECT_THROW(fetchable_files_restricted_id->perform_action(action), ActionFailedError);
     }
@@ -1024,7 +1023,7 @@ TEST(ERepository, ManifestCheck)
 
     const std::shared_ptr<const PackageID> id(*env[selection::AllVersionsSorted(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("category/package",
-                            &env, { })), make_null_shared_ptr(), { }))]->last());
+                            &env, { })), nullptr, { }))]->last());
     ASSERT_TRUE(bool(id));
     repo->make_manifest(id->name());
     id->perform_action(action);
@@ -1052,7 +1051,7 @@ TEST(ERepository, ParseEAPI)
     };
     auto ids(env[selection::AllVersionsSorted(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("category/package",
-                            &env, { })), make_null_shared_ptr(), { }))]);
+                            &env, { })), nullptr, { }))]);
 
     int i(0);
     for (auto it(ids->begin()), it_end(ids->end()); it_end != it; ++i, ++it)
diff --git a/paludis/repositories/e/e_repository_TEST_0.cc b/paludis/repositories/e/e_repository_TEST_0.cc
index fccec254e..43733e7b7 100644
--- a/paludis/repositories/e/e_repository_TEST_0.cc
+++ b/paludis/repositories/e/e_repository_TEST_0.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -129,7 +128,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/in-ebuild-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -137,7 +136,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/in-subshell-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -145,7 +144,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -153,7 +152,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/unpack-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -161,7 +160,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/econf-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -169,7 +168,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/emake-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -177,7 +176,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/emake-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -185,7 +184,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/einstall-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -193,7 +192,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/keepdir-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -201,7 +200,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/dobin-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -209,7 +208,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/dobin-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -217,7 +216,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/fperms-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -225,7 +224,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/fperms-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -233,7 +232,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-source-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
@@ -242,7 +241,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -251,7 +250,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_prepare-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -260,7 +259,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_configure-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -269,7 +268,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/best-version-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -277,7 +276,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/has-version-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -285,7 +284,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/match-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -293,7 +292,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/vars-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -301,7 +300,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/expand-vars-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -309,7 +308,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-disable-dependency-tracking-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -318,7 +317,7 @@ TEST(ERepository, InstallEAPI0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/use-with-enable-empty-third-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
diff --git a/paludis/repositories/e/e_repository_TEST_1.cc b/paludis/repositories/e/e_repository_TEST_1.cc
index cffc50d5f..ca97d0f53 100644
--- a/paludis/repositories/e/e_repository_TEST_1.cc
+++ b/paludis/repositories/e/e_repository_TEST_1.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -126,7 +125,7 @@ TEST(ERepository, InstallEAPI1)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-source-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("1", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -135,7 +134,7 @@ TEST(ERepository, InstallEAPI1)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/dosym-success-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("1", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -144,7 +143,7 @@ TEST(ERepository, InstallEAPI1)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("1", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -153,7 +152,7 @@ TEST(ERepository, InstallEAPI1)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_prepare-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("1", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -162,7 +161,7 @@ TEST(ERepository, InstallEAPI1)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_configure-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("1", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
diff --git a/paludis/repositories/e/e_repository_TEST_2.cc b/paludis/repositories/e/e_repository_TEST_2.cc
index 0319a56da..175de8b12 100644
--- a/paludis/repositories/e/e_repository_TEST_2.cc
+++ b/paludis/repositories/e/e_repository_TEST_2.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -126,7 +125,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-source-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -135,7 +134,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -144,7 +143,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_prepare-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
@@ -153,7 +152,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_configure-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         ASSERT_THROW(id->perform_action(action), ActionFailedError);
@@ -162,7 +161,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/default-src_configure-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -171,7 +170,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/default-src_compile-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -180,7 +179,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/default_src_compile-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -189,7 +188,7 @@ TEST(ERepository, InstallEAPI2)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/src_compile-via-default-func-2",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("2", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
diff --git a/paludis/repositories/e/e_repository_TEST_3.cc b/paludis/repositories/e/e_repository_TEST_3.cc
index 522db226c..758a0f3d1 100644
--- a/paludis/repositories/e/e_repository_TEST_3.cc
+++ b/paludis/repositories/e/e_repository_TEST_3.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -126,7 +125,7 @@ TEST(ERepository, InstallEAPI3)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/prefix-3",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("3", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
diff --git a/paludis/repositories/e/e_repository_TEST_4.cc b/paludis/repositories/e/e_repository_TEST_4.cc
index 7fe5b1e71..a59014d1a 100644
--- a/paludis/repositories/e/e_repository_TEST_4.cc
+++ b/paludis/repositories/e/e_repository_TEST_4.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -133,7 +132,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/pkg_pretend-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -149,7 +148,7 @@ TEST(ERepository, InstallEAPI4)
                     ));
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/pkg_pretend-failure-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action2);
@@ -159,7 +158,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/default_src_install-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -168,7 +167,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/docompress-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -177,7 +176,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/dodoc-r-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -186,7 +185,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doins-symlink-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -195,7 +194,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/banned-functions-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
@@ -204,7 +203,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-disable-dependency-tracking-4_beta",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -213,7 +212,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-disable-dependency-tracking-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -222,7 +221,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/global-scope-use-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -231,7 +230,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -240,7 +239,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/use-with-enable-empty-third-4",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -248,7 +247,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/no-eapi5-commands-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -258,7 +257,7 @@ TEST(ERepository, InstallEAPI4)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/no-new-stdin-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -306,7 +305,7 @@ TEST(ERepository, EAPI4MergeType)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/merge-type-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -376,7 +375,7 @@ TEST(ERepository, EAPI4MergeTypeBin)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/merge-type-bin-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -394,7 +393,7 @@ TEST(ERepository, EAPI4MergeTypeBin)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/merge-type-bin-4::binrepo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("pbin-1+4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -441,7 +440,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-all-good-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -457,7 +456,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-all-empty-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -473,7 +472,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-all-one-not-good-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -489,7 +488,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-any-good-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -505,7 +504,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-any-empty-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -521,7 +520,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-any-none-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -537,7 +536,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-one-none-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -553,7 +552,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-one-none-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -569,7 +568,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-one-good-4::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("4", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
diff --git a/paludis/repositories/e/e_repository_TEST_5.cc b/paludis/repositories/e/e_repository_TEST_5.cc
index 68e0db589..dcb86c65e 100644
--- a/paludis/repositories/e/e_repository_TEST_5.cc
+++ b/paludis/repositories/e/e_repository_TEST_5.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -135,7 +134,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-disable-silent-rules-5",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -144,7 +143,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/usex-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -154,7 +153,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/new-stdin-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -163,7 +162,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doheader-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -172,7 +171,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doheader-dies-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
@@ -181,7 +180,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/strict-use-5",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -190,7 +189,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/strict-use-fail-5",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
@@ -199,7 +198,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/strict-use-injection-5",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(action);
@@ -208,7 +207,7 @@ TEST(ERepository, InstallEAPI5)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/ebuild-phase-func-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -254,7 +253,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-at-most-one-none-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -270,7 +269,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-at-most-one-one-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -286,7 +285,7 @@ TEST(ERepository, RequiredUse)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/required-use-at-most-one-two-5::test-repo",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(pretend_action);
@@ -338,7 +337,7 @@ TEST(ERepository, SubSlots)
         {
             const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/subslots-5",
-                                    &env, { })), make_null_shared_ptr(), { }))]->last());
+                                    &env, { })), nullptr, { }))]->last());
             ASSERT_TRUE(bool(id));
             EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
             EXPECT_EQ("foo/bar", id->slot_key()->parse_value().raw_value());
@@ -354,7 +353,7 @@ TEST(ERepository, SubSlots)
         {
             const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/subslots-5::installed",
-                                    &env, { })), make_null_shared_ptr(), { }))]->last());
+                                    &env, { })), nullptr, { }))]->last());
             ASSERT_TRUE(bool(id));
             EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
             EXPECT_EQ("foo/bar", id->slot_key()->parse_value().raw_value());
@@ -366,7 +365,7 @@ TEST(ERepository, SubSlots)
         {
             const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/subslot-dep-5",
-                                    &env, { })), make_null_shared_ptr(), { }))]->last());
+                                    &env, { })), nullptr, { }))]->last());
             ASSERT_TRUE(bool(id));
             EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
             EXPECT_EQ("cat/subslots:= cat/subslots:foo=", id->build_dependencies_key()->pretty_print_value(UnformattedPrettyPrinter(), { }));
@@ -378,7 +377,7 @@ TEST(ERepository, SubSlots)
         {
             const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                             PackageDepSpec(parse_user_package_dep_spec("=cat/subslot-dep-5::installed",
-                                    &env, { })), make_null_shared_ptr(), { }))]->last());
+                                    &env, { })), nullptr, { }))]->last());
             ASSERT_TRUE(bool(id));
             EXPECT_EQ("5", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
             EXPECT_EQ("cat/subslots:foo/bar= cat/subslots:foo/bar=", id->build_dependencies_key()->pretty_print_value(UnformattedPrettyPrinter(), { }));
diff --git a/paludis/repositories/e/e_repository_TEST_ever.cc b/paludis/repositories/e/e_repository_TEST_ever.cc
index cdd9637d2..5d6ecf7bf 100644
--- a/paludis/repositories/e/e_repository_TEST_ever.cc
+++ b/paludis/repositories/e/e_repository_TEST_ever.cc
@@ -32,7 +32,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/stringify.hh>
 
 #include <paludis/output_manager.hh>
@@ -137,7 +136,7 @@ TEST_P(EverTest, Works)
 
     const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("cat/" + test,
-                            &env, { })), make_null_shared_ptr(), { }))]->last());
+                            &env, { })), nullptr, { }))]->last());
     ASSERT_TRUE(bool(id));
     id->perform_action(action);
 }
diff --git a/paludis/repositories/e/e_repository_TEST_exheres_0.cc b/paludis/repositories/e/e_repository_TEST_exheres_0.cc
index 01202e28f..10b90f9f8 100644
--- a/paludis/repositories/e/e_repository_TEST_exheres_0.cc
+++ b/paludis/repositories/e/e_repository_TEST_exheres_0.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/safe_ifstream.hh>
 
@@ -128,7 +127,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/in-ebuild-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -136,7 +135,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/in-subshell-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -144,7 +143,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -152,7 +151,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/expatch-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -160,7 +159,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/expatch-success-dir",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -168,7 +167,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/expatch-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -176,7 +175,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/expatch-unrecognised",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -184,7 +183,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-expatch-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -192,7 +191,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-expatch-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -200,7 +199,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/unpack-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -208,7 +207,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-unpack-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -216,7 +215,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-unpack-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -224,7 +223,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/econf-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -232,7 +231,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-econf",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -240,7 +239,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-econf-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -248,7 +247,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/emake-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -256,7 +255,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-emake",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -264,7 +263,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-emake-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -272,7 +271,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/einstall-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -280,7 +279,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-einstall",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -288,7 +287,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-einstall-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -296,7 +295,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/keepdir-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -304,7 +303,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/keepdir-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -312,7 +311,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-keepdir",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -320,7 +319,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-keepdir-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -328,7 +327,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/dobin-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -336,7 +335,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/dobin-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -344,7 +343,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-dobin-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -352,7 +351,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-dobin-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -360,7 +359,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/nonfatal-dobin-die",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -368,7 +367,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/herebin-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -376,7 +375,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/herebin-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -384,7 +383,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereconfd-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -392,7 +391,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereconfd-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -400,7 +399,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereenvd-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -408,7 +407,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereenvd-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -416,7 +415,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereinitd-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -424,7 +423,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereinitd-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -432,7 +431,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereins-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -440,7 +439,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/hereins-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -448,7 +447,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/heresbin-success",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -456,7 +455,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("cat/heresbin-fail",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -464,7 +463,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/best-version-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -472,7 +471,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/has-version-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -480,7 +479,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/match-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -488,7 +487,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-phase-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -496,7 +495,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/econf-vars-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -504,7 +503,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/expand-vars-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -512,7 +511,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-success-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -520,7 +519,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-nonfatal-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -528,7 +527,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/doman-failure-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -536,7 +535,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/change-globals-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -544,7 +543,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/install-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -552,7 +551,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/install-s-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -560,7 +559,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/global-optionq-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -568,7 +567,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/expecting-tests-enabled-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -576,7 +575,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/expecting-tests-disabled-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
@@ -584,7 +583,7 @@ TEST(ERepository, InstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/expecting-tests-none-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -629,7 +628,7 @@ TEST(ERepository, ReallyInstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/exdirectory-phase-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -637,7 +636,7 @@ TEST(ERepository, ReallyInstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/exdirectory-forbid-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_THROW(id->perform_action(action), ActionFailedError);
     }
@@ -645,7 +644,7 @@ TEST(ERepository, ReallyInstallExheres0)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/exdirectory-allow-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         id->perform_action(action);
     }
diff --git a/paludis/repositories/e/e_repository_TEST_exlibs.cc b/paludis/repositories/e/e_repository_TEST_exlibs.cc
index ac9cd405a..8fe42a8c0 100644
--- a/paludis/repositories/e/e_repository_TEST_exlibs.cc
+++ b/paludis/repositories/e/e_repository_TEST_exlibs.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/stringify.hh>
 
 #include <paludis/package_id.hh>
@@ -153,7 +152,7 @@ TEST_P(ExlibsTest, Works)
 
     const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("cat/" + info.test,
-                            &env, { })), make_null_shared_ptr(), { }))]->last());
+                            &env, { })), nullptr, { }))]->last());
     ASSERT_TRUE(bool(id));
     switch (info.expected_result)
     {
diff --git a/paludis/repositories/e/e_repository_TEST_pbin.cc b/paludis/repositories/e/e_repository_TEST_pbin.cc
index 3f94e5537..5bab3bf3d 100644
--- a/paludis/repositories/e/e_repository_TEST_pbin.cc
+++ b/paludis/repositories/e/e_repository_TEST_pbin.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/fs_stat.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -161,7 +160,7 @@ TEST_P(ERepositoryInstallEAPIPBinTest, Works)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/simple-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ(base_eapi, visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(bin_action);
@@ -181,7 +180,7 @@ TEST_P(ERepositoryInstallEAPIPBinTest, Works)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/simple-1::binrepo" + base_eapi,
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("pbin-1+" + base_eapi, visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(install_action);
@@ -261,7 +260,7 @@ TEST(Symlinks, Works)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/symlinks-1",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("exheres-0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(bin_action);
@@ -283,7 +282,7 @@ TEST(Symlinks, Works)
 
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/symlinks-1::binrepoexheres-0",
-                                &env, { })), make_null_shared_ptr(), { }))]->last());
+                                &env, { })), nullptr, { }))]->last());
         ASSERT_TRUE(bool(id));
         EXPECT_EQ("pbin-1+exheres-0", visitor_cast<const MetadataValueKey<std::string> >(**id->find_metadata("EAPI"))->parse_value());
         id->perform_action(install_action);
diff --git a/paludis/repositories/e/e_repository_TEST_phases.cc b/paludis/repositories/e/e_repository_TEST_phases.cc
index b48c3af7e..187fb8555 100644
--- a/paludis/repositories/e/e_repository_TEST_phases.cc
+++ b/paludis/repositories/e/e_repository_TEST_phases.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/stringify.hh>
 
 #include <paludis/output_manager.hh>
@@ -149,7 +148,7 @@ TEST_P(PhasesTest, Works)
 
     const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("cat/" + info.test,
-                            &env, { })), make_null_shared_ptr(), { }))]->last());
+                            &env, { })), nullptr, { }))]->last());
     ASSERT_TRUE(bool(id));
     EXPECT_EQ(info.expect_expensive_test, !! id->choices_key()->parse_value()->find_by_name_with_prefix(
                 ChoiceNameWithPrefix("build_options:expensive_tests")));
diff --git a/paludis/repositories/e/e_repository_TEST_replacing.cc b/paludis/repositories/e/e_repository_TEST_replacing.cc
index 7c28a0a71..335cb3b68 100644
--- a/paludis/repositories/e/e_repository_TEST_replacing.cc
+++ b/paludis/repositories/e/e_repository_TEST_replacing.cc
@@ -29,7 +29,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/map.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/stringify.hh>
 
 #include <paludis/package_id.hh>
@@ -140,7 +139,7 @@ TEST_P(ReplacingTest, Works)
 
     const std::shared_ptr<const PackageIDSequence> rlist(env[selection::AllVersionsSorted(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(info.replacing, &env, { })),
-                    make_null_shared_ptr(), { }) |
+                    nullptr, { }) |
                 filter::InstalledAtRoot(env.preferred_root_key()->parse_value()))]);
 
     InstallAction action(make_named_values<InstallActionOptions>(
@@ -153,7 +152,7 @@ TEST_P(ReplacingTest, Works)
 
     const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("cat/" + info.test,
-                            &env, { })), make_null_shared_ptr(), { }) |
+                            &env, { })), nullptr, { }) |
                 filter::SupportsAction<InstallAction>())]->last());
     ASSERT_TRUE(bool(id));
     id->perform_action(action);
diff --git a/paludis/repositories/e/e_repository_TEST_symlink_rewriting.cc b/paludis/repositories/e/e_repository_TEST_symlink_rewriting.cc
index 5f8ce76b7..20364918e 100644
--- a/paludis/repositories/e/e_repository_TEST_symlink_rewriting.cc
+++ b/paludis/repositories/e/e_repository_TEST_symlink_rewriting.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/safe_ifstream.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/stringify.hh>
 
 #include <paludis/standard_output_manager.hh>
@@ -128,7 +127,7 @@ TEST(ERepository, SymlinkRewriting)
 
     const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("cat/pkg",
-                            &env, { })), make_null_shared_ptr(), { }))]->last());
+                            &env, { })), nullptr, { }))]->last());
     ASSERT_TRUE(bool(id));
 
     id->perform_action(action);
diff --git a/paludis/repositories/e/e_repository_news.cc b/paludis/repositories/e/e_repository_news.cc
index 193419cbd..5e0653cfe 100644
--- a/paludis/repositories/e/e_repository_news.cc
+++ b/paludis/repositories/e/e_repository_news.cc
@@ -33,7 +33,6 @@
 #include <paludis/util/fs_path.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/fs_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/environment.hh>
 #include <paludis/distribution.hh>
@@ -177,7 +176,7 @@ ERepositoryNews::update_news() const
                     if (! (*_imp->environment)[selection::SomeArbitraryVersion(
                                 generator::Matches(PackageDepSpec(parse_elike_package_dep_spec(*i,
                                             eapi.supported()->package_dep_spec_parse_options(),
-                                            eapi.supported()->version_spec_options())), make_null_shared_ptr(), { }) |
+                                            eapi.supported()->version_spec_options())), nullptr, { }) |
                                 filter::InstalledAtRoot(_imp->environment->preferred_root_key()->parse_value()))]->empty())
                         local_show = true;
                 show &= local_show;
diff --git a/paludis/repositories/e/e_repository_sets.cc b/paludis/repositories/e/e_repository_sets.cc
index 2f60c1def..254568b52 100644
--- a/paludis/repositories/e/e_repository_sets.cc
+++ b/paludis/repositories/e/e_repository_sets.cc
@@ -46,7 +46,6 @@
 #include <paludis/util/is_file_with_extension.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/pimp-impl.hh>
 #include <paludis/util/sequence.hh>
 #include <paludis/util/set.hh>
@@ -131,7 +130,7 @@ ERepositorySets::package_set(const SetName & ss) const
         return f.contents();
     }
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 std::shared_ptr<const SetNameSet>
@@ -180,7 +179,7 @@ namespace
             {
                 PackageDepSpec spec(parse_elike_package_dep_spec(stringify(id->name()) + ":" + r.slot(), eapi.supported()->package_dep_spec_parse_options(),
                             eapi.supported()->version_spec_options()));
-                if (! match_package(*env, spec, id, make_null_shared_ptr(), { }))
+                if (! match_package(*env, spec, id, nullptr, { }))
                     return false;
             }
             catch (const SlotNameError &)
diff --git a/paludis/repositories/e/ebuild.cc b/paludis/repositories/e/ebuild.cc
index 815263504..8e8771225 100644
--- a/paludis/repositories/e/ebuild.cc
+++ b/paludis/repositories/e/ebuild.cc
@@ -40,7 +40,6 @@
 #include <paludis/util/indirect_iterator-impl.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/env_var_names.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/about.hh>
 #include <paludis/environment.hh>
@@ -1066,8 +1065,8 @@ WriteVDBEntryCommand::operator() ()
                               std::bind(&pipe_command_handler,
                                         params.environment(),
                                         params.package_id(),
-                                        make_null_shared_ptr(),
-                                        make_null_shared_ptr(), false, _1,
+                                        nullptr,
+                                        nullptr, false, _1,
                                         params.maybe_output_manager()));
 
     if (! params.package_id()->eapi()->supported()->ebuild_metadata_variables()->iuse_effective()->name().empty())
@@ -1330,8 +1329,8 @@ WriteBinaryEbuildCommand::operator() ()
                               std::bind(&pipe_command_handler,
                                         params.environment(),
                                         params.package_id(),
-                                        make_null_shared_ptr(),
-                                        make_null_shared_ptr(), false, _1,
+                                        nullptr,
+                                        nullptr, false, _1,
                                         params.maybe_output_manager()));
 
     if (! params.package_id()->eapi()->supported()->ebuild_metadata_variables()->scm_revision()->name().empty())
diff --git a/paludis/repositories/e/ebuild_flat_metadata_cache_TEST.cc b/paludis/repositories/e/ebuild_flat_metadata_cache_TEST.cc
index 9aecb84d1..91db754da 100644
--- a/paludis/repositories/e/ebuild_flat_metadata_cache_TEST.cc
+++ b/paludis/repositories/e/ebuild_flat_metadata_cache_TEST.cc
@@ -38,7 +38,6 @@
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/timestamp.hh>
 #include <paludis/util/fs_stat.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/join.hh>
 #include <paludis/util/stringify.hh>
 
@@ -83,7 +82,7 @@ TEST(EbuildFlatMetadataCache, FlatList)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_list", id->short_description_key()->parse_value());
@@ -105,7 +104,7 @@ TEST(EbuildFlatMetadataCache, FlatListStale)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_list-stale", id1->short_description_key()->parse_value());
@@ -128,7 +127,7 @@ TEST(EbuildFlatMetadataCache, GuessedEAPI)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-guessed-eapi-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_list-guessed-eapi", id1->short_description_key()->parse_value());
@@ -150,7 +149,7 @@ TEST(EbuildFlatMetadataCache, EclassCached)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-eclass-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_list-eclass", id->short_description_key()->parse_value());
@@ -175,7 +174,7 @@ TEST(EbuildFlatMetadataCache, EclassStale)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-eclass-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_list-eclass-stale", id1->short_description_key()->parse_value());
@@ -197,7 +196,7 @@ TEST(EbuildFlatMetadataCache, EclassWrong)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-eclass-wrong-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_list-eclass-wrong", id1->short_description_key()->parse_value());
@@ -219,7 +218,7 @@ TEST(EbuildFlatMetadataCache, EclassGone)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-eclass-gone-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_list-eclass-gone", id1->short_description_key()->parse_value());
@@ -241,7 +240,7 @@ TEST(EbuildFlatMetadataCache, FlatListDetection)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_list-detection-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_list-detection", id->short_description_key()->parse_value());
@@ -263,7 +262,7 @@ TEST(EbuildFlatMetadataCache, FlatHash)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash", id->short_description_key()->parse_value());
@@ -286,7 +285,7 @@ TEST(EbuildFlatMetadataCache, FlatHashGuessedEAPI)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-guessed-eapi-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-guessed-eapi", id1->short_description_key()->parse_value());
@@ -308,7 +307,7 @@ TEST(EbuildFlatMetadataCache, FlatHashGuessedExtension)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-guessed-eapi-extension-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-guessed-eapi-extension", id1->short_description_key()->parse_value());
@@ -330,7 +329,7 @@ TEST(EbuildFlatMetadataCache, FlatHashNoGuessedEAPI)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-no-guessed-eapi-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-no-guessed-eapi", id->short_description_key()->parse_value());
@@ -352,7 +351,7 @@ TEST(EbuildFlatMetadataCache, EmptyValue)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-empty-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("", id->short_description_key()->parse_value());
@@ -375,7 +374,7 @@ TEST(EbuildFlatMetadataCache, HashStale)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-stale", id1->short_description_key()->parse_value());
@@ -397,7 +396,7 @@ TEST(EbuildFlatMetadataCache, HashNoMTime)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-no-mtime-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-no-mtime", id1->short_description_key()->parse_value());
@@ -419,7 +418,7 @@ TEST(EbuildFlatMetadataCache, HashNoMTimeStale)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-no-mtime-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-no-mtime-stale", id1->short_description_key()->parse_value());
@@ -441,7 +440,7 @@ TEST(EbuildFlatMetadataCache, HashBadMtime)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-bad-mtime-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-bad-mtime", id1->short_description_key()->parse_value());
@@ -463,7 +462,7 @@ TEST(EbuildFlatMetadataCache, HashMD5)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-md5-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Description flat_hash-md5", id1->short_description_key()->parse_value());
@@ -485,7 +484,7 @@ TEST(EbuildFlatMetadataCache, HashBadMD5)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-bad-md5-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-bad-md5", id1->short_description_key()->parse_value());
@@ -507,7 +506,7 @@ TEST(EbuildFlatMetadataCache, HashNoEAPI)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-no-eapi-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Description flat_hash-no-eapi", id1->short_description_key()->parse_value());
@@ -529,7 +528,7 @@ TEST(EbuildFlatMetadataCache, HashDuplicateKey)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-duplicate-key-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id1->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-duplicate-key", id1->short_description_key()->parse_value());
@@ -551,7 +550,7 @@ TEST(EbuildFlatMetadataCache, HashEclass)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-eclass", id->short_description_key()->parse_value());
@@ -575,7 +574,7 @@ TEST(EbuildFlatMetadataCache, HashEclassStale)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclass-stale", id->short_description_key()->parse_value());
@@ -597,7 +596,7 @@ TEST(EbuildFlatMetadataCache, HashEclassWrong)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-wrong-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclass-wrong", id->short_description_key()->parse_value());
@@ -618,7 +617,7 @@ TEST(EbuildFlatMetadataCache, HashEclassGone)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-gone-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclass-gone", id->short_description_key()->parse_value());
@@ -640,7 +639,7 @@ TEST(EbuildFlatMetadataCache, HashFullEclass)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-full-eclass-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-full-eclass", id->short_description_key()->parse_value());
@@ -664,7 +663,7 @@ TEST(EbuildFlatMetadataCache, HashFullEclassNonStandard)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-full-eclass-nonstandard-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-full-eclass-nonstandard", id->short_description_key()->parse_value());
@@ -688,7 +687,7 @@ TEST(EbuildFlatMetadataCache, HashFullEclassStale)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-full-eclass-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-full-eclass-stale", id->short_description_key()->parse_value());
@@ -710,7 +709,7 @@ TEST(EbuildFlatMetadataCache, HashFullEclassWrong)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-full-eclass-wrong-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-full-eclass-wrong", id->short_description_key()->parse_value());
@@ -732,7 +731,7 @@ TEST(EbuildFlatMetadataCache, HashFullEclassGone)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-full-eclass-gone-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-full-eclass-gone", id->short_description_key()->parse_value());
@@ -754,14 +753,14 @@ TEST(EbuildFlatMetadataCache, HashEclassTruncated)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclasses-truncated-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclasses-truncated", id->short_description_key()->parse_value());
 
     std::shared_ptr<const PackageID> id2(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclasses-truncated-2",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id2->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclasses-truncated-2", id2->short_description_key()->parse_value());
@@ -783,7 +782,7 @@ TEST(EbuildFlatMetadataCache, HashEclassBadMtime)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclasses-bad-mtime-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclasses-bad-mtime", id->short_description_key()->parse_value());
@@ -805,7 +804,7 @@ TEST(EbuildFlatMetadataCache, HashEclassSpaces)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclasses-spaces-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclasses-spaces", id->short_description_key()->parse_value());
@@ -827,7 +826,7 @@ TEST(EbuildFlatMetadataCache, HashEclassMD5)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-md5-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Description flat_hash-eclass-md5", id->short_description_key()->parse_value());
@@ -849,7 +848,7 @@ TEST(EbuildFlatMetadataCache, HashEclassBadMD5)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-bad-md5-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclass-bad-md5", id->short_description_key()->parse_value());
@@ -871,7 +870,7 @@ TEST(EbuildFlatMetadataCache, HashEclassTruncatedMD5)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-truncated-md5-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclass-truncated-md5", id->short_description_key()->parse_value());
@@ -893,7 +892,7 @@ TEST(EbuildFlatMetadataCache, HashEclassGoneMD5)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-eclass-gone-md5-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-eclass-gone-md5", id->short_description_key()->parse_value());
@@ -916,7 +915,7 @@ TEST(EbuildFlatMetadataCache, HashExlib)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlib-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-exlib", id->short_description_key()->parse_value());
@@ -941,7 +940,7 @@ TEST(EbuildFlatMetadataCache, HashExlibPerCategory)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlib-percat-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("the-description-flat_hash-exlib-percat", id->short_description_key()->parse_value());
@@ -966,7 +965,7 @@ TEST(EbuildFlatMetadataCache, HashExlibStale)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlib-stale-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlib-stale", id->short_description_key()->parse_value());
@@ -989,7 +988,7 @@ TEST(EbuildFlatMetadataCache, HashExlibWrong)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlib-wrong-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlib-wrong", id->short_description_key()->parse_value());
@@ -1012,7 +1011,7 @@ TEST(EbuildFlatMetadataCache, HashExlibGone)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlib-gone-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlib-gone", id->short_description_key()->parse_value());
@@ -1035,14 +1034,14 @@ TEST(EbuildFlatMetadataCache, HashExlibTruncated)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlibs-truncated-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlibs-truncated", id->short_description_key()->parse_value());
 
     std::shared_ptr<const PackageID> id2(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlibs-truncated-2",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id2->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlibs-truncated-2", id2->short_description_key()->parse_value());
@@ -1065,7 +1064,7 @@ TEST(EbuildFlatMetadataCache, HashExlibBadMtime)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlibs-bad-mtime-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlibs-bad-mtime", id->short_description_key()->parse_value());
@@ -1088,7 +1087,7 @@ TEST(EbuildFlatMetadataCache, HashExlibSpaces)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/flat_hash-exlibs-spaces-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ("The Generated Description flat_hash-exlibs-spaces", id->short_description_key()->parse_value());
@@ -1111,7 +1110,7 @@ TEST(EbuildFlatMetadataCache, Write)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/write-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ(contents("ebuild_flat_metadata_cache_TEST_dir/cache/expected/cat/write-1"), contents("ebuild_flat_metadata_cache_TEST_dir/cache/test-repo/cat/write-1"));
@@ -1135,7 +1134,7 @@ TEST(EbuildFlatMetadataCache, Write1)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/write-eapi1-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ(contents("ebuild_flat_metadata_cache_TEST_dir/cache/expected/cat/write-eapi1-1"), contents("ebuild_flat_metadata_cache_TEST_dir/cache/test-repo/cat/write-eapi1-1"));
@@ -1161,7 +1160,7 @@ TEST(EbuildFlatMetadataCache, WriteEclasses)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/write-eclasses-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ(contents("ebuild_flat_metadata_cache_TEST_dir/cache/expected/cat/write-eclasses-1"), contents("ebuild_flat_metadata_cache_TEST_dir/cache/test-repo/cat/write-eclasses-1"));
@@ -1186,7 +1185,7 @@ TEST(EbuildFlatMetadataCache, WriteExlibs)
 
     std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat/write-exlibs-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(id->short_description_key()));
     EXPECT_EQ(contents("ebuild_flat_metadata_cache_TEST_dir/cache/expected/cat/write-exlibs-1"), contents("ebuild_flat_metadata_cache_TEST_dir/cache/test-repo/cat/write-exlibs-1"));
diff --git a/paludis/repositories/e/ebuild_id.cc b/paludis/repositories/e/ebuild_id.cc
index cdc8f8088..ffb59a345 100644
--- a/paludis/repositories/e/ebuild_id.cc
+++ b/paludis/repositories/e/ebuild_id.cc
@@ -62,7 +62,6 @@
 #include <paludis/util/wrapped_output_iterator.hh>
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/destringify.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/accept_visitor.hh>
@@ -313,11 +312,11 @@ EbuildID::need_non_xml_keys_added() const
                     n::environment() = _imp->environment,
                     n::exlibsdirs() = e_repo->layout()->exlibsdirs(name()),
                     n::files_dir() = e_repo->layout()->package_directory(name()) / "files",
-                    n::maybe_output_manager() = make_null_shared_ptr(),
+                    n::maybe_output_manager() = nullptr,
                     n::package_builddir() = e_repo->params().builddir() / (stringify(name().category()) + "-" + stringify(name().package()) + "-" + stringify(version()) + "-metadata"),
                     n::package_id() = shared_from_this(),
-                    n::parts() = make_null_shared_ptr(),
-                    n::permitted_directories() = make_null_shared_ptr(),
+                    n::parts() = nullptr,
+                    n::permitted_directories() = nullptr,
                     n::portdir() =
                         (e_repo->params().master_repositories() && ! e_repo->params().master_repositories()->empty()) ?
                         (*e_repo->params().master_repositories()->begin())->params().location() : e_repo->params().location(),
@@ -424,7 +423,7 @@ EbuildID::need_non_xml_keys_added() const
     }
     else
         _imp->choices = std::make_shared<EChoicesKey>(_imp->environment, shared_from_this(), "PALUDIS_CHOICES", "Choices", mkt_normal,
-                    e_repo, std::bind(return_literal_function(make_null_shared_ptr())));
+                    e_repo, std::bind(return_literal_function(nullptr)));
     add_metadata_key(_imp->choices);
 }
 
@@ -543,7 +542,7 @@ EbuildID::choice_descriptions() const
     if (m)
         return m->uses();
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 namespace
@@ -959,7 +958,7 @@ EbuildID::from_repositories_key() const
         return _imp->generated_from;
     }
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
@@ -1805,6 +1804,6 @@ EbuildID::set_scm_revision(const std::string & s) const
 const std::shared_ptr<const Contents>
 EbuildID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/e/exheres_layout.cc b/paludis/repositories/e/exheres_layout.cc
index 4be51e146..b5f9c8fde 100644
--- a/paludis/repositories/e/exheres_layout.cc
+++ b/paludis/repositories/e/exheres_layout.cc
@@ -38,7 +38,6 @@
 #include <paludis/util/set.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
 #include <paludis/util/hashes.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_iterator.hh>
 #include <paludis/util/fs_stat.hh>
 
@@ -653,13 +652,13 @@ ExheresLayout::accounts_repository_data_location_key() const
         return std::make_shared<LiteralMetadataValueKey<FSPath>>("accounts_repository_data_location",
                     "AccountsRepository data location", mkt_internal, _imp->tree_root / "metadata" / "accounts");
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 std::shared_ptr<MetadataValueKey<FSPath> >
 ExheresLayout::e_updates_location_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 std::shared_ptr<MetadataValueKey<FSPath> >
@@ -669,7 +668,7 @@ ExheresLayout::licence_groups_location_key() const
         return std::make_shared<LiteralMetadataValueKey<FSPath>>("licence_groups_location",
                     "License groups data location", mkt_internal, _imp->tree_root / "metadata" / "licence_groups.conf");
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 std::shared_ptr<const MasksInfo>
diff --git a/paludis/repositories/e/exheres_mask_store.cc b/paludis/repositories/e/exheres_mask_store.cc
index 6b8eea4f1..5813c0e90 100644
--- a/paludis/repositories/e/exheres_mask_store.cc
+++ b/paludis/repositories/e/exheres_mask_store.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/hashes.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/log.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/fs_stat.hh>
@@ -157,7 +156,7 @@ ExheresMaskStore::_populate()
         try
         {
             auto specs(parse_commented_set(file_text, _imp->env, *EAPIData::get_instance()->eapi_from_string(_imp->eapi_for_file(*f))));
-            DepSpecFlattener<SetSpecTree, PackageDepSpec> flat_specs(_imp->env, make_null_shared_ptr());
+            DepSpecFlattener<SetSpecTree, PackageDepSpec> flat_specs(_imp->env, nullptr);
             specs->top()->accept(flat_specs);
 
             for (auto s(flat_specs.begin()), s_end(flat_specs.end()) ;
@@ -191,7 +190,7 @@ ExheresMaskStore::query(const std::shared_ptr<const PackageID> & id) const
     auto r(_imp->repo_mask.find(id->name()));
     if (_imp->repo_mask.end() != r)
         for (auto k(r->second.begin()), k_end(r->second.end()) ; k != k_end ; ++k)
-            if (match_package(*_imp->env, k->first, id, make_null_shared_ptr(), { }))
+            if (match_package(*_imp->env, k->first, id, nullptr, { }))
                 result->push_back(*k->second);
 
     return result;
diff --git a/paludis/repositories/e/exheres_profile.cc b/paludis/repositories/e/exheres_profile.cc
index de84491a7..4abf76752 100644
--- a/paludis/repositories/e/exheres_profile.cc
+++ b/paludis/repositories/e/exheres_profile.cc
@@ -34,7 +34,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/hashes.hh>
 #include <paludis/util/system.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/safe_ifstream.hh>
 
@@ -135,18 +134,18 @@ ExheresProfile::ExheresProfile(
         _load_dir(*l);
 
     const std::shared_ptr<const Set<UnprefixedChoiceName> > s(_imp->options_conf.known_choice_value_names(
-                make_null_shared_ptr(), ChoicePrefixName("suboptions")));
+                nullptr, ChoicePrefixName("suboptions")));
     for (Set<UnprefixedChoiceName>::ConstIterator f(s->begin()), f_end(s->end()) ;
             f != f_end ; ++f)
-        if (_imp->options_conf.want_choice_enabled_locked(make_null_shared_ptr(),
+        if (_imp->options_conf.want_choice_enabled_locked(nullptr,
                     ChoicePrefixName("suboptions"), *f).first.is_true())
             _imp->use_expand->insert(stringify(*f));
 
     const std::shared_ptr<const Set<UnprefixedChoiceName> > sh(_imp->options_conf.known_choice_value_names(
-                make_null_shared_ptr(), ChoicePrefixName("hidden_suboptions")));
+                nullptr, ChoicePrefixName("hidden_suboptions")));
     for (Set<UnprefixedChoiceName>::ConstIterator f(sh->begin()), f_end(sh->end()) ;
             f != f_end ; ++f)
-        if (_imp->options_conf.want_choice_enabled_locked(make_null_shared_ptr(),
+        if (_imp->options_conf.want_choice_enabled_locked(nullptr,
                     ChoicePrefixName("hidden_suboptions"), *f).first.is_true())
             _imp->use_expand_hidden->insert(stringify(*f));
 }
@@ -185,7 +184,7 @@ ExheresProfile::_load_dir(const FSPath & f)
             auto eapi(EAPIData::get_instance()->eapi_from_string(_imp->eapi_for_file(f / "system.conf")));
             auto specs(parse_commented_set(file_text, _imp->env, *EAPIData::get_instance()->eapi_from_string(_imp->eapi_for_file(f / "system.conf"))));
 
-            DepSpecFlattener<SetSpecTree, PackageDepSpec> flat_specs(_imp->env, make_null_shared_ptr());
+            DepSpecFlattener<SetSpecTree, PackageDepSpec> flat_specs(_imp->env, nullptr);
             specs->top()->accept(flat_specs);
 
             for (auto s(flat_specs.begin()), s_end(flat_specs.end()) ;
diff --git a/paludis/repositories/e/exndbam_repository.cc b/paludis/repositories/e/exndbam_repository.cc
index 7064b2f95..ca14dae10 100644
--- a/paludis/repositories/e/exndbam_repository.cc
+++ b/paludis/repositories/e/exndbam_repository.cc
@@ -35,7 +35,6 @@
 #include <paludis/util/system.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/safe_ifstream.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/fs_iterator.hh>
 #include <paludis/util/join.hh>
@@ -292,7 +291,7 @@ ExndbamRepository::installed_root_key() const
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 ExndbamRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 void
@@ -475,7 +474,7 @@ ExndbamRepository::merge(const MergeParams & m)
                             std::placeholders::_1),
                     n::is_overwrite() = true,
                     n::make_output_manager() = std::bind(&this_output_manager, m.output_manager(), std::placeholders::_1),
-                    n::override_contents() = make_null_shared_ptr(),
+                    n::override_contents() = nullptr,
                     n::want_phase() = m.want_phase()
                     ));
         m.perform_uninstall()(if_overwritten_id, uo);
@@ -498,7 +497,7 @@ ExndbamRepository::merge(const MergeParams & m)
                                     std::placeholders::_1),
                             n::is_overwrite() = false,
                             n::make_output_manager() = std::bind(&this_output_manager, m.output_manager(), std::placeholders::_1),
-                            n::override_contents() = make_null_shared_ptr(),
+                            n::override_contents() = nullptr,
                             n::want_phase() = m.want_phase()
                             ));
                 m.perform_uninstall()(candidate, uo);
@@ -638,8 +637,8 @@ ExndbamRepository::perform_uninstall(
                         n::maybe_output_manager() = output_manager,
                         n::package_builddir() = package_builddir,
                         n::package_id() = id,
-                        n::parts() = make_null_shared_ptr(),
-                        n::permitted_directories() = make_null_shared_ptr(),
+                        n::parts() = nullptr,
+                        n::permitted_directories() = nullptr,
                         n::portdir() = _imp->params.location(),
                         n::root() = stringify(_imp->params.root()),
                         n::sandbox() = phase->option("sandbox"),
diff --git a/paludis/repositories/e/exndbam_repository_TEST.cc b/paludis/repositories/e/exndbam_repository_TEST.cc
index 3c77d8377..0809628d8 100644
--- a/paludis/repositories/e/exndbam_repository_TEST.cc
+++ b/paludis/repositories/e/exndbam_repository_TEST.cc
@@ -28,7 +28,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/sequence.hh>
 #include <paludis/util/fs_path.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/standard_output_manager.hh>
 #include <paludis/action.hh>
@@ -81,7 +80,7 @@ namespace
         if (! victim.empty())
             replacing->push_back(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(victim,
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
         InstallAction install_action(make_named_values<InstallActionOptions>(
                     n::destination() = exndbam_repo,
                     n::make_output_manager() = &make_standard_output_manager,
@@ -91,7 +90,7 @@ namespace
                 ));
         (*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(chosen_one,
-                            &env, { })), make_null_shared_ptr(), { }))]->begin())->perform_action(install_action);
+                            &env, { })), nullptr, { }))]->begin())->perform_action(install_action);
     }
 
     std::shared_ptr<Repository>
diff --git a/paludis/repositories/e/fetch_visitor_TEST.cc b/paludis/repositories/e/fetch_visitor_TEST.cc
index 239c62f99..24025d90f 100644
--- a/paludis/repositories/e/fetch_visitor_TEST.cc
+++ b/paludis/repositories/e/fetch_visitor_TEST.cc
@@ -29,7 +29,6 @@
 #include <paludis/util/sequence.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/fs_stat.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/stringify.hh>
 
@@ -77,7 +76,7 @@ TEST(FetchVisitor, Works)
     const std::shared_ptr<const EAPI> eapi(EAPIData::get_instance()->eapi_from_string("exheres-0"));
     FetchVisitor v(&env, *env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("=cat/pkg-1",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin(),
+                        &env, { }), nullptr, { }))]->begin(),
             *eapi, FSPath("fetch_visitor_TEST_dir/out"),
             false, false, "test", std::make_shared<URIListedThenMirrorsLabel>("listed-then-mirrors"), false,
             std::make_shared<StandardOutputManager>(), get_mirrors_fn);
diff --git a/paludis/repositories/e/fix_locked_dependencies.cc b/paludis/repositories/e/fix_locked_dependencies.cc
index a825e2743..84156d6d2 100644
--- a/paludis/repositories/e/fix_locked_dependencies.cc
+++ b/paludis/repositories/e/fix_locked_dependencies.cc
@@ -25,7 +25,6 @@
 #include <paludis/util/options.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
 #include <paludis/util/accept_visitor.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/dep_spec.hh>
 #include <paludis/environment.hh>
 #include <paludis/package_id.hh>
@@ -55,17 +54,17 @@ namespace
 
         std::shared_ptr<const SlotRequirement> visit(const SlotExactPartialRequirement &) const
         {
-            return make_null_shared_ptr();
+            return nullptr;
         }
 
         std::shared_ptr<const SlotRequirement> visit(const SlotExactFullRequirement &) const
         {
-            return make_null_shared_ptr();
+            return nullptr;
         }
 
         std::shared_ptr<const SlotRequirement> visit(const SlotAnyUnlockedRequirement &) const
         {
-            return make_null_shared_ptr();
+            return nullptr;
         }
 
         std::shared_ptr<const SlotRequirement> rewrite() const
@@ -73,7 +72,7 @@ namespace
             std::shared_ptr<const PackageIDSequence> matches((*env)[selection::AllVersionsSorted(
                         generator::Matches(*spec, id, { }) | filter::InstalledAtRoot(env->system_root_key()->parse_value()))]);
             if (matches->empty())
-                return make_null_shared_ptr();
+                return nullptr;
 
             if ((*matches->last())->slot_key())
             {
@@ -89,7 +88,7 @@ namespace
                     return std::make_shared<ELikeSlotExactPartialRequirement>(ss.match_values().first, spec->slot_requirement_ptr());
             }
             else
-                return make_null_shared_ptr();
+                return nullptr;
         }
 
         std::shared_ptr<const SlotRequirement> visit(const SlotAnyPartialLockedRequirement &) const
diff --git a/paludis/repositories/e/info_metadata_key.cc b/paludis/repositories/e/info_metadata_key.cc
index f90ad2585..8a8fa83ee 100644
--- a/paludis/repositories/e/info_metadata_key.cc
+++ b/paludis/repositories/e/info_metadata_key.cc
@@ -31,7 +31,6 @@
 #include <paludis/util/indirect_iterator-impl.hh>
 #include <paludis/util/join.hh>
 #include <paludis/util/fs_stat.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/literal_metadata_key.hh>
 #include <paludis/selection.hh>
@@ -188,7 +187,7 @@ InfoPkgsMetadataKey::need_keys_added() const
             std::shared_ptr<const PackageIDSequence> q((*_imp->env)[selection::AllVersionsSorted(
                         generator::Matches(parse_elike_package_dep_spec(i->first,
                                 eapi->supported()->package_dep_spec_parse_options(),
-                                eapi->supported()->version_spec_options()), make_null_shared_ptr(), { }) |
+                                eapi->supported()->version_spec_options()), nullptr, { }) |
                         filter::InstalledAtRoot(_imp->env->preferred_root_key()->parse_value()))]);
 
             if (q->empty())
diff --git a/paludis/repositories/e/licence_groups.cc b/paludis/repositories/e/licence_groups.cc
index c0be7ec0b..609a2f16f 100644
--- a/paludis/repositories/e/licence_groups.cc
+++ b/paludis/repositories/e/licence_groups.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/set.hh>
 #include <paludis/util/options.hh>
 #include <paludis/util/wrapped_output_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <vector>
 #include <map>
@@ -85,11 +84,11 @@ LicenceGroups::maybe_expand_licence_nonrecursively(const std::string & s) const
     {
         auto i(_imp->store.find(s.substr(1)));
         if (_imp->store.end() == i)
-            return make_null_shared_ptr();
+            return nullptr;
         else
             return i->second;
     }
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
diff --git a/paludis/repositories/e/myoptions_requirements_verifier.cc b/paludis/repositories/e/myoptions_requirements_verifier.cc
index 542bd1f4d..6b8eae682 100644
--- a/paludis/repositories/e/myoptions_requirements_verifier.cc
+++ b/paludis/repositories/e/myoptions_requirements_verifier.cc
@@ -28,7 +28,6 @@
 #include <paludis/util/log.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/accept_visitor.hh>
 #include <paludis/choice.hh>
 #include <paludis/metadata_key.hh>
@@ -115,7 +114,7 @@ namespace
             }
         }
 
-        return make_null_shared_ptr();
+        return nullptr;
     }
 }
 
diff --git a/paludis/repositories/e/parse_annotations.cc b/paludis/repositories/e/parse_annotations.cc
index 8d7dd1ad5..cd8b5ff1a 100644
--- a/paludis/repositories/e/parse_annotations.cc
+++ b/paludis/repositories/e/parse_annotations.cc
@@ -24,7 +24,6 @@
 #include <paludis/util/stringify.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/dep_spec_annotations.hh>
 
 using namespace paludis;
diff --git a/paludis/repositories/e/traditional_layout.cc b/paludis/repositories/e/traditional_layout.cc
index 5ca63317c..6d8b56865 100644
--- a/paludis/repositories/e/traditional_layout.cc
+++ b/paludis/repositories/e/traditional_layout.cc
@@ -36,7 +36,6 @@
 #include <paludis/util/set.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
 #include <paludis/util/hashes.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/fs_iterator.hh>
 #include <paludis/util/active_object_ptr.hh>
@@ -671,7 +670,7 @@ TraditionalLayout::binary_ebuild_directory(const QualifiedPackageName & q) const
 std::shared_ptr<MetadataValueKey<FSPath> >
 TraditionalLayout::accounts_repository_data_location_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 std::shared_ptr<MetadataValueKey<FSPath> >
@@ -681,7 +680,7 @@ TraditionalLayout::e_updates_location_key() const
         return std::make_shared<LiteralMetadataValueKey<FSPath>>("e_updates_location",
                     "VDBRepository updates data location", mkt_internal, _imp->tree_root / "profiles" / "updates");
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 std::shared_ptr<MetadataValueKey<FSPath> >
@@ -691,7 +690,7 @@ TraditionalLayout::licence_groups_location_key() const
         return std::make_shared<LiteralMetadataValueKey<FSPath>>("licence_groups_location",
                     "License groups data location", mkt_internal, _imp->tree_root / "profiles" / "license_groups");
     else
-        return make_null_shared_ptr();
+        return nullptr;
 }
 
 std::shared_ptr<const MasksInfo>
diff --git a/paludis/repositories/e/traditional_mask_store.cc b/paludis/repositories/e/traditional_mask_store.cc
index 28d5292a2..3017bcdbc 100644
--- a/paludis/repositories/e/traditional_mask_store.cc
+++ b/paludis/repositories/e/traditional_mask_store.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/hashes.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/log.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/dep_spec.hh>
 #include <paludis/package_id.hh>
 #include <paludis/match_package.hh>
@@ -125,7 +124,7 @@ TraditionalMaskStore::query(const std::shared_ptr<const PackageID> & id) const
     auto r(_imp->repo_mask.find(id->name()));
     if (_imp->repo_mask.end() != r)
         for (auto k(r->second.begin()), k_end(r->second.end()) ; k != k_end ; ++k)
-            if (match_package(*_imp->env, k->first, id, make_null_shared_ptr(), { }))
+            if (match_package(*_imp->env, k->first, id, nullptr, { }))
                 result->push_back(*k->second);
 
     return result;
diff --git a/paludis/repositories/e/traditional_profile.cc b/paludis/repositories/e/traditional_profile.cc
index cf34e713f..fd72b4fed 100644
--- a/paludis/repositories/e/traditional_profile.cc
+++ b/paludis/repositories/e/traditional_profile.cc
@@ -42,7 +42,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/fs_error.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/upper_lower.hh>
 
 #include <paludis/choice.hh>
@@ -831,7 +830,7 @@ TraditionalProfile::use_masked(
         for (PackageFlagStatusMapList::const_iterator g(i->package_use_mask.begin()),
                 g_end(i->package_use_mask.end()) ; g != g_end ; ++g)
         {
-            if (! match_package(*_imp->env, *g->first, id, make_null_shared_ptr(), { }))
+            if (! match_package(*_imp->env, *g->first, id, nullptr, { }))
                 continue;
 
             FlagStatusMap::const_iterator h(g->second.find(value_prefixed));
@@ -844,7 +843,7 @@ TraditionalProfile::use_masked(
             for (PackageFlagStatusMapList::const_iterator gs(i->package_use_stable_mask.begin()),
                      gs_end(i->package_use_stable_mask.end()) ; gs != gs_end ; ++gs)
             {
-                if (! match_package(*_imp->env, *gs->first, id, make_null_shared_ptr(), { }))
+                if (! match_package(*_imp->env, *gs->first, id, nullptr, { }))
                     continue;
 
                 FlagStatusMap::const_iterator hs(gs->second.find(value_prefixed));
@@ -888,7 +887,7 @@ TraditionalProfile::use_forced(
         for (PackageFlagStatusMapList::const_iterator g(i->package_use_force.begin()),
                 g_end(i->package_use_force.end()) ; g != g_end ; ++g)
         {
-            if (! match_package(*_imp->env, *g->first, id, make_null_shared_ptr(), { }))
+            if (! match_package(*_imp->env, *g->first, id, nullptr, { }))
                 continue;
 
             FlagStatusMap::const_iterator h(g->second.find(value_prefixed));
@@ -901,7 +900,7 @@ TraditionalProfile::use_forced(
             for (PackageFlagStatusMapList::const_iterator gs(i->package_use_stable_force.begin()),
                      gs_end(i->package_use_stable_force.end()) ; gs != gs_end ; ++gs)
             {
-                if (! match_package(*_imp->env, *gs->first, id, make_null_shared_ptr(), { }))
+                if (! match_package(*_imp->env, *gs->first, id, nullptr, { }))
                     continue;
 
                 FlagStatusMap::const_iterator hs(gs->second.find(value_prefixed));
@@ -931,7 +930,7 @@ TraditionalProfile::use_state_ignoring_masks(
         for (PackageFlagStatusMapList::const_iterator g(i->package_use.begin()),
                 g_end(i->package_use.end()) ; g != g_end ; ++g)
         {
-            if (! match_package(*_imp->env, *g->first, id, make_null_shared_ptr(), { }))
+            if (! match_package(*_imp->env, *g->first, id, nullptr, { }))
                 continue;
 
             FlagStatusMap::const_iterator h(g->second.find(value_prefixed));
@@ -1032,7 +1031,7 @@ TraditionalProfile::profile_masks(const std::shared_ptr<const PackageID> & id) c
     {
         for (std::list<std::pair<std::shared_ptr<const PackageDepSpec>, std::shared_ptr<const MaskInfo> > >::const_iterator k(rr->second.begin()),
                 k_end(rr->second.end()) ; k != k_end ; ++k)
-            if (match_package(*_imp->env, *k->first, id, make_null_shared_ptr(), { }))
+            if (match_package(*_imp->env, *k->first, id, nullptr, { }))
                 result->push_back(*k->second);
     }
 
diff --git a/paludis/repositories/e/vdb_merger.cc b/paludis/repositories/e/vdb_merger.cc
index af74b35ec..9312f22bd 100644
--- a/paludis/repositories/e/vdb_merger.cc
+++ b/paludis/repositories/e/vdb_merger.cc
@@ -1,7 +1,7 @@
 /* vim: set sw=4 sts=4 et foldmethod=syntax : */
 
 /*
- * Copyright (c) 2007, 2008, 2009, 2010, 2011 Ciaran McCreesh
+ * Copyright (c) 2007, 2008, 2009, 2010, 2011, 2013 Ciaran McCreesh
  *
  * This file is part of the Paludis package manager. Paludis is free software;
  * you can redistribute it and/or modify it under the terms of the GNU General
@@ -30,7 +30,7 @@
 #include <paludis/util/strip.hh>
 #include <paludis/util/options.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
+#include <paludis/util/enum_iterator.hh>
 #include <paludis/util/timestamp.hh>
 #include <paludis/util/env_var_names.hh>
 #include <paludis/util/safe_ofstream.hh>
@@ -98,7 +98,7 @@ VDBMerger::VDBMerger(const VDBMergerParams & p) :
                 n::merged_entries() = p.merged_entries(),
                 n::no_chown() = ! getenv_with_default(env_vars::no_chown, "").empty(),
                 n::options() = p.options(),
-                n::parts() = make_null_shared_ptr(),
+                n::parts() = nullptr,
                 n::permit_destination() = p.permit_destination(),
                 n::root() = p.root()
             )),
diff --git a/paludis/repositories/e/vdb_repository.cc b/paludis/repositories/e/vdb_repository.cc
index eb5f44a20..b7fd7b5a0 100644
--- a/paludis/repositories/e/vdb_repository.cc
+++ b/paludis/repositories/e/vdb_repository.cc
@@ -68,7 +68,6 @@
 #include <paludis/util/tokeniser.hh>
 #include <paludis/util/hashes.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/visitor_cast.hh>
 #include <paludis/util/wrapped_output_iterator.hh>
 #include <paludis/util/safe_ifstream.hh>
@@ -508,8 +507,8 @@ VDBRepository::perform_uninstall(
                     n::maybe_output_manager() = output_manager,
                     n::package_builddir() = package_builddir,
                     n::package_id() = id,
-                    n::parts() = make_null_shared_ptr(),
-                    n::permitted_directories() = make_null_shared_ptr(),
+                    n::parts() = nullptr,
+                    n::permitted_directories() = nullptr,
                     n::portdir() = _imp->params.location(),
                     n::root() = stringify(_imp->params.root()),
                     n::sandbox() = phase->option("sandbox"),
@@ -783,7 +782,7 @@ VDBRepository::merge(const MergeParams & m)
                                     std::placeholders::_1),
                             n::is_overwrite() = false,
                             n::make_output_manager() = std::bind(&this_output_manager, m.output_manager(), std::placeholders::_1),
-                            n::override_contents() = make_null_shared_ptr(),
+                            n::override_contents() = nullptr,
                             n::want_phase() = m.want_phase()
                             ));
                 m.perform_uninstall()(candidate, uo);
@@ -927,7 +926,7 @@ VDBRepository::installed_root_key() const
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 VDBRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace
@@ -1206,7 +1205,7 @@ VDBRepository::perform_updates()
                             SlotName old_slot(tokens.at(2)), new_slot(tokens.at(3));
 
                             const std::shared_ptr<const PackageIDSequence> ids((*_imp->params.environment())[selection::AllVersionsSorted(
-                                        (generator::Matches(old_spec, make_null_shared_ptr(), { }) & generator::InRepository(name())) |
+                                        (generator::Matches(old_spec, nullptr, { }) & generator::InRepository(name())) |
                                         filter::Slot(old_slot)
                                         )]);
                             if (! ids->empty())
diff --git a/paludis/repositories/e/vdb_repository_TEST.cc b/paludis/repositories/e/vdb_repository_TEST.cc
index 5c1c36fa6..1f22fc428 100644
--- a/paludis/repositories/e/vdb_repository_TEST.cc
+++ b/paludis/repositories/e/vdb_repository_TEST.cc
@@ -46,7 +46,6 @@
 #include <paludis/contents.hh>
 
 #include <paludis/util/indirect_iterator-impl.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <functional>
 #include <algorithm>
@@ -134,7 +133,7 @@ namespace
         if (! victim.empty())
             replacing->push_back(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(victim,
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
         InstallAction install_action(make_named_values<InstallActionOptions>(
                     n::destination() = vdb_repo,
                     n::make_output_manager() = &make_standard_output_manager,
@@ -144,7 +143,7 @@ namespace
                 ));
         (*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(chosen_one,
-                            &env, { })), make_null_shared_ptr(), { }))]->begin())->perform_action(install_action);
+                            &env, { })), nullptr, { }))]->begin())->perform_action(install_action);
     }
 }
 
@@ -191,7 +190,7 @@ TEST(VDBRepository, QueryUse)
 
     std::shared_ptr<const PackageID> e1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
 
     ASSERT_TRUE(bool(e1->choices_key()));
     ASSERT_TRUE(bool(e1->choices_key()->parse_value()));
@@ -220,7 +219,7 @@ TEST(VDBRepository, Contents)
 
     std::shared_ptr<const PackageID> e1(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec("=cat-one/pkg-one-1",
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
     ContentsGatherer gatherer;
     auto contents(e1->contents());
     std::for_each(indirect_iterator(contents->begin()),
@@ -313,7 +312,7 @@ TEST(VDBRepository, Reinstall)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/pkg-1::reinstalltest_src1",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         id->perform_action(install_action);
         vdb_repo->invalidate();
 
@@ -324,7 +323,7 @@ TEST(VDBRepository, Reinstall)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/pkg-1::reinstalltest_src1",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         id->perform_action(install_action);
         vdb_repo->invalidate();
 
@@ -335,7 +334,7 @@ TEST(VDBRepository, Reinstall)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/pkg-1::reinstalltest_src2",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         id->perform_action(install_action);
         vdb_repo->invalidate();
 
diff --git a/paludis/repositories/e/vdb_repository_TEST_cache.cc b/paludis/repositories/e/vdb_repository_TEST_cache.cc
index 835db4031..7863128e4 100644
--- a/paludis/repositories/e/vdb_repository_TEST_cache.cc
+++ b/paludis/repositories/e/vdb_repository_TEST_cache.cc
@@ -32,7 +32,6 @@
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/metadata_key.hh>
 #include <paludis/standard_output_manager.hh>
@@ -97,7 +96,7 @@ namespace
         if (! victim.empty())
             replacing->push_back(*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(victim,
-                            &env, { })), make_null_shared_ptr(), { }))]->begin());
+                            &env, { })), nullptr, { }))]->begin());
         InstallAction install_action(make_named_values<InstallActionOptions>(
                     n::destination() = vdb_repo,
                     n::make_output_manager() = &make_standard_output_manager,
@@ -107,7 +106,7 @@ namespace
                 ));
         (*env[selection::RequireExactlyOne(generator::Matches(
                     PackageDepSpec(parse_user_package_dep_spec(chosen_one,
-                            &env, { })), make_null_shared_ptr(), { }))]->begin())->perform_action(install_action);
+                            &env, { })), nullptr, { }))]->begin())->perform_action(install_action);
     }
 
     void read_cache(const FSPath & names_cache, std::vector<FSPath> & vec)
@@ -163,11 +162,11 @@ TEST(NamesCache, Incremental)
 
     UninstallAction uninstall_action(make_named_values<UninstallActionOptions>(
                 n::config_protect() = "",
-                n::if_for_install_id() = make_null_shared_ptr(),
+                n::if_for_install_id() = nullptr,
                 n::ignore_for_unmerge() = &ignore_nothing,
                 n::is_overwrite() = false,
                 n::make_output_manager() = &make_standard_output_manager,
-                n::override_contents() = make_null_shared_ptr(),
+                n::override_contents() = nullptr,
                 n::want_phase() = &want_all_phases
             ));
 
@@ -235,7 +234,7 @@ TEST(NamesCache, Incremental)
     {
         const std::shared_ptr<const PackageID> inst_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat1/pkg1-2::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         inst_id->perform_action(uninstall_action);
         vdb_repo->invalidate();
 
@@ -262,7 +261,7 @@ TEST(NamesCache, Incremental)
     {
         const std::shared_ptr<const PackageID> inst_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat1/pkg2-1::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         inst_id->perform_action(uninstall_action);
         vdb_repo->invalidate();
 
@@ -287,7 +286,7 @@ TEST(NamesCache, Incremental)
     {
         const std::shared_ptr<const PackageID> inst_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat2/pkg1-1::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         inst_id->perform_action(uninstall_action);
         vdb_repo->invalidate();
 
@@ -301,7 +300,7 @@ TEST(NamesCache, Incremental)
     {
         const std::shared_ptr<const PackageID> inst_id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat1/pkg1-1::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         inst_id->perform_action(uninstall_action);
         vdb_repo->invalidate();
 
diff --git a/paludis/repositories/e/vdb_repository_TEST_eapis.cc b/paludis/repositories/e/vdb_repository_TEST_eapis.cc
index b4bc85bf0..ce7c15217 100644
--- a/paludis/repositories/e/vdb_repository_TEST_eapis.cc
+++ b/paludis/repositories/e/vdb_repository_TEST_eapis.cc
@@ -45,7 +45,6 @@
 #include <paludis/unformatted_pretty_printer.hh>
 
 #include <paludis/util/indirect_iterator-impl.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <functional>
 #include <algorithm>
@@ -140,11 +139,11 @@ TEST_P(PhasesTest, Works)
 
     UninstallAction uninstall_action(make_named_values<UninstallActionOptions>(
                 n::config_protect() = "",
-                n::if_for_install_id() = make_null_shared_ptr(),
+                n::if_for_install_id() = nullptr,
                 n::ignore_for_unmerge() = &ignore_nothing,
                 n::is_overwrite() = false,
                 n::make_output_manager() = &make_standard_output_manager,
-                n::override_contents() = make_null_shared_ptr(),
+                n::override_contents() = nullptr,
                 n::want_phase() = &want_all_phases
             ));
 
@@ -162,7 +161,7 @@ TEST_P(PhasesTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::srcrepo",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(install_action);
     }
@@ -172,7 +171,7 @@ TEST_P(PhasesTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::srcrepo",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(install_action);
     }
@@ -182,7 +181,7 @@ TEST_P(PhasesTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(info_action);
     }
@@ -190,7 +189,7 @@ TEST_P(PhasesTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(config_action);
     }
@@ -198,7 +197,7 @@ TEST_P(PhasesTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(uninstall_action);
     }
@@ -267,11 +266,11 @@ TEST_P(VarsTest, Works)
 
     UninstallAction uninstall_action(make_named_values<UninstallActionOptions>(
                 n::config_protect() = "",
-                n::if_for_install_id() = make_null_shared_ptr(),
+                n::if_for_install_id() = nullptr,
                 n::ignore_for_unmerge() = &ignore_nothing,
                 n::is_overwrite() = false,
                 n::make_output_manager() = &make_standard_output_manager,
-                n::override_contents() = make_null_shared_ptr(),
+                n::override_contents() = nullptr,
                 n::want_phase() = &want_all_phases
             ));
 
@@ -289,7 +288,7 @@ TEST_P(VarsTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::srcrepo",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(install_action);
     }
@@ -299,7 +298,7 @@ TEST_P(VarsTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::srcrepo",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(install_action);
     }
@@ -309,7 +308,7 @@ TEST_P(VarsTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(info_action);
     }
@@ -317,7 +316,7 @@ TEST_P(VarsTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(config_action);
     }
@@ -325,7 +324,7 @@ TEST_P(VarsTest, Works)
     {
         const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(generator::Matches(
                         PackageDepSpec(parse_user_package_dep_spec("=cat/target-" + eapi + "::installed",
-                                &env, { })), make_null_shared_ptr(), { }))]->begin());
+                                &env, { })), nullptr, { }))]->begin());
         ASSERT_TRUE(bool(id));
         id->perform_action(uninstall_action);
     }
diff --git a/paludis/repositories/e/vdb_unmerger_TEST.cc b/paludis/repositories/e/vdb_unmerger_TEST.cc
index 37c3809db..199f63063 100644
--- a/paludis/repositories/e/vdb_unmerger_TEST.cc
+++ b/paludis/repositories/e/vdb_unmerger_TEST.cc
@@ -30,7 +30,6 @@
 #include <paludis/util/wrapped_forward_iterator.hh>
 #include <paludis/util/sequence.hh>
 #include <paludis/util/fs_stat.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 
 #include <paludis/standard_output_manager.hh>
 #include <paludis/user_dep_spec.hh>
@@ -117,7 +116,7 @@ namespace
             env.add_repository(0, repo);
 
             auto id(*env[selection::RequireExactlyOne(generator::Matches(
-                            parse_user_package_dep_spec("cat/" + fix(what), &env, { }), make_null_shared_ptr(), { }))]->begin());
+                            parse_user_package_dep_spec("cat/" + fix(what), &env, { }), nullptr, { }))]->begin());
 
             unmerger = std::make_shared<VDBUnmergerNoDisplay>(make_named_values<VDBUnmergerOptions>(
                             n::config_protect() = "/protected_file /protected_dir",
diff --git a/paludis/repositories/fake/fake_installed_repository.cc b/paludis/repositories/fake/fake_installed_repository.cc
index b54aab1c9..a4922accb 100644
--- a/paludis/repositories/fake/fake_installed_repository.cc
+++ b/paludis/repositories/fake/fake_installed_repository.cc
@@ -21,7 +21,6 @@
 #include <paludis/util/sequence.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
 #include <paludis/package_id.hh>
 #include <paludis/metadata_key.hh>
@@ -209,12 +208,12 @@ FakeInstalledRepository::repository_factory_dependencies(
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 FakeInstalledRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Set<std::string> >
 FakeInstalledRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/fake/fake_package_id.cc b/paludis/repositories/fake/fake_package_id.cc
index 440b3be7a..5858a101e 100644
--- a/paludis/repositories/fake/fake_package_id.cc
+++ b/paludis/repositories/fake/fake_package_id.cc
@@ -44,7 +44,6 @@
 #include <paludis/util/tribool.hh>
 #include <paludis/util/wrapped_output_iterator.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
 #include <paludis/util/accept_visitor.hh>
@@ -469,7 +468,7 @@ namespace
 
         virtual const std::shared_ptr<const PermittedChoiceValueParameterValues> permitted_parameter_values() const
         {
-            return make_null_shared_ptr();
+            return nullptr;
         }
 
         virtual bool presumed() const PALUDIS_ATTRIBUTE((warn_unused_result))
@@ -804,7 +803,7 @@ FakePackageID::post_dependencies_key()
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
 FakePackageID::dependencies_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<FetchableURISpecTree> >
@@ -1198,7 +1197,7 @@ FakePackageID::behaviours_set()
 const std::shared_ptr<const Contents>
 FakePackageID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/fake/fake_repository.cc b/paludis/repositories/fake/fake_repository.cc
index dea5a108b..1c7853420 100644
--- a/paludis/repositories/fake/fake_repository.cc
+++ b/paludis/repositories/fake/fake_repository.cc
@@ -24,7 +24,6 @@
 #include <paludis/util/sequence.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/distribution.hh>
 #include <paludis/environment.hh>
 #include <paludis/package_id.hh>
@@ -151,12 +150,12 @@ FakeRepository::installed_root_key() const
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 FakeRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Set<std::string> >
 FakeRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/gemcutter/gemcutter_id.cc b/paludis/repositories/gemcutter/gemcutter_id.cc
index 3e12a5f52..06a891563 100644
--- a/paludis/repositories/gemcutter/gemcutter_id.cc
+++ b/paludis/repositories/gemcutter/gemcutter_id.cc
@@ -27,7 +27,6 @@
 #include <paludis/util/set.hh>
 #include <paludis/util/hashes.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/name.hh>
@@ -47,7 +46,7 @@ namespace
             const std::string & r, const std::string & h, const MetadataKeyType t, const std::string & v)
     {
         if (v.empty())
-            return make_null_shared_ptr();
+            return nullptr;
         else
             return std::make_shared<LiteralMetadataValueKey<std::string> >(r, h, t, v);
     }
@@ -56,7 +55,7 @@ namespace
             const std::string * const r, const std::string * const h, const MetadataKeyType t, const std::string & v)
     {
         if (v.empty())
-            return make_null_shared_ptr();
+            return nullptr;
         else
             return std::make_shared<GemcutterURIKey>(r, h, t, v);
     }
@@ -331,7 +330,7 @@ GemcutterID::fs_location_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 GemcutterID::behaviours_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<KeywordNameSet> >
@@ -397,13 +396,13 @@ GemcutterID::installed_time_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 GemcutterID::from_repositories_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::shared_ptr<const Choices> > >
 GemcutterID::choices_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<Slot> >
@@ -415,7 +414,7 @@ GemcutterID::slot_key() const
 const std::shared_ptr<const Contents>
 GemcutterID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/gemcutter/gemcutter_repository.cc b/paludis/repositories/gemcutter/gemcutter_repository.cc
index 381febbdc..4bdad242d 100644
--- a/paludis/repositories/gemcutter/gemcutter_repository.cc
+++ b/paludis/repositories/gemcutter/gemcutter_repository.cc
@@ -29,7 +29,6 @@
 #include <paludis/util/simple_parser.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/safe_ofstream.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/literal_metadata_key.hh>
 #include <paludis/action.hh>
@@ -131,7 +130,7 @@ GemcutterRepository::location_key() const
 const std::shared_ptr<const MetadataValueKey<FSPath> >
 GemcutterRepository::installed_root_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 void
@@ -299,13 +298,13 @@ GemcutterRepository::perform_hook(const Hook &, const std::shared_ptr<OutputMana
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 GemcutterRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Set<std::string> >
 GemcutterRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/repository/repository_id.cc b/paludis/repositories/repository/repository_id.cc
index f35a6b095..27e70077d 100644
--- a/paludis/repositories/repository/repository_id.cc
+++ b/paludis/repositories/repository/repository_id.cc
@@ -25,7 +25,6 @@
 #include <paludis/util/set.hh>
 #include <paludis/util/hashes.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/name.hh>
 #include <paludis/version_spec.hh>
@@ -225,7 +224,7 @@ RepositoryID::post_dependencies_key() const
 const std::shared_ptr<const MetadataValueKey<std::string> >
 RepositoryID::short_description_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::string> >
@@ -255,25 +254,25 @@ RepositoryID::installed_time_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 RepositoryID::from_repositories_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::shared_ptr<const Choices> > >
 RepositoryID::choices_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<Slot> >
 RepositoryID::slot_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Contents>
 RepositoryID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/repository/repository_repository.cc b/paludis/repositories/repository/repository_repository.cc
index ac7598c21..99f73ddce 100644
--- a/paludis/repositories/repository/repository_repository.cc
+++ b/paludis/repositories/repository/repository_repository.cc
@@ -29,7 +29,6 @@
 #include <paludis/util/simple_parser.hh>
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/safe_ofstream.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/literal_metadata_key.hh>
 #include <paludis/action.hh>
@@ -136,7 +135,7 @@ RepositoryRepository::format_key() const
 const std::shared_ptr<const MetadataValueKey<FSPath> >
 RepositoryRepository::location_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<FSPath> >
@@ -320,7 +319,7 @@ RepositoryRepository::perform_hook(const Hook &, const std::shared_ptr<OutputMan
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 RepositoryRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 bool
@@ -475,7 +474,7 @@ RepositoryRepository::merge(const MergeParams & m)
 const std::shared_ptr<const Set<std::string> >
 RepositoryRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/unavailable/unavailable_package_id.cc b/paludis/repositories/unavailable/unavailable_package_id.cc
index 0108f230a..b3f729c02 100644
--- a/paludis/repositories/unavailable/unavailable_package_id.cc
+++ b/paludis/repositories/unavailable/unavailable_package_id.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/set.hh>
 #include <paludis/util/hashes.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/make_named_values.hh>
 
 #include <paludis/name.hh>
@@ -217,7 +216,7 @@ UnavailablePackageID::fs_location_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 UnavailablePackageID::behaviours_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<KeywordNameSet> >
@@ -301,7 +300,7 @@ UnavailablePackageID::slot_key() const
 const std::shared_ptr<const Contents>
 UnavailablePackageID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/unavailable/unavailable_repository.cc b/paludis/repositories/unavailable/unavailable_repository.cc
index 61af1e1a3..051b64bcc 100644
--- a/paludis/repositories/unavailable/unavailable_repository.cc
+++ b/paludis/repositories/unavailable/unavailable_repository.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/tokeniser.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/extract_host_from_url.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/literal_metadata_key.hh>
 #include <paludis/action.hh>
 #include <paludis/syncer.hh>
@@ -457,7 +456,7 @@ UnavailableRepository::sync_host_key() const
 const std::shared_ptr<const Set<std::string> >
 UnavailableRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/unavailable/unavailable_repository_id.cc b/paludis/repositories/unavailable/unavailable_repository_id.cc
index 764cec4da..1cf0d97e8 100644
--- a/paludis/repositories/unavailable/unavailable_repository_id.cc
+++ b/paludis/repositories/unavailable/unavailable_repository_id.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/hashes.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/name.hh>
@@ -229,7 +228,7 @@ UnavailableRepositoryID::perform_action(Action & action) const
                 n::options() = MergerOptions(),
                 n::output_manager() = output_manager,
                 n::package_id() = shared_from_this(),
-                n::parts() = make_null_shared_ptr(),
+                n::parts() = nullptr,
                 n::perform_uninstall() = install_action->options.perform_uninstall(),
                 n::permit_destination() = std::bind(return_literal_function(true)),
                 n::replacing() = install_action->options.replacing(),
@@ -289,7 +288,7 @@ UnavailableRepositoryID::perform_action(Action & action) const
                     n::is_overwrite() = false,
                     n::make_output_manager() = std::bind(
                             &this_output_manager, output_manager, std::placeholders::_1),
-                    n::override_contents() = make_null_shared_ptr(),
+                    n::override_contents() = nullptr,
                     n::want_phase() = install_action->options.want_phase()
                     ));
         install_action->options.perform_uninstall()(*i, uo);
@@ -391,25 +390,25 @@ UnavailableRepositoryID::installed_time_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 UnavailableRepositoryID::from_repositories_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<std::shared_ptr<const Choices> > >
 UnavailableRepositoryID::choices_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<Slot> >
 UnavailableRepositoryID::slot_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Contents>
 UnavailableRepositoryID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/unavailable/unavailable_repository_store.cc b/paludis/repositories/unavailable/unavailable_repository_store.cc
index 95e4fd61d..4434465ec 100644
--- a/paludis/repositories/unavailable/unavailable_repository_store.cc
+++ b/paludis/repositories/unavailable/unavailable_repository_store.cc
@@ -32,7 +32,6 @@
 #include <paludis/util/is_file_with_extension.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/make_named_values.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_iterator.hh>
 #include <paludis/name.hh>
 #include <paludis/version_spec.hh>
diff --git a/paludis/repositories/unpackaged/installed_id.cc b/paludis/repositories/unpackaged/installed_id.cc
index 63535375a..6400f8f9a 100644
--- a/paludis/repositories/unpackaged/installed_id.cc
+++ b/paludis/repositories/unpackaged/installed_id.cc
@@ -30,7 +30,6 @@
 #include <paludis/util/safe_ifstream.hh>
 #include <paludis/util/return_literal_function.hh>
 #include <paludis/util/timestamp.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/fs_iterator.hh>
 #include <paludis/util/fs_stat.hh>
@@ -503,7 +502,7 @@ InstalledUnpackagedID::keywords_key() const
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
 InstalledUnpackagedID::dependencies_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
diff --git a/paludis/repositories/unpackaged/installed_repository.cc b/paludis/repositories/unpackaged/installed_repository.cc
index 7763261c5..4e5c2564c 100644
--- a/paludis/repositories/unpackaged/installed_repository.cc
+++ b/paludis/repositories/unpackaged/installed_repository.cc
@@ -32,7 +32,6 @@
 #include <paludis/util/indirect_iterator-impl.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
 #include <paludis/util/safe_ofstream.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_iterator.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/return_literal_function.hh>
@@ -516,12 +515,12 @@ InstalledUnpackagedRepository::sync(
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 InstalledUnpackagedRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Set<std::string> >
 InstalledUnpackagedRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/unpackaged/installed_repository_TEST.cc b/paludis/repositories/unpackaged/installed_repository_TEST.cc
index 7dc3d8a41..1fbbaca3f 100644
--- a/paludis/repositories/unpackaged/installed_repository_TEST.cc
+++ b/paludis/repositories/unpackaged/installed_repository_TEST.cc
@@ -40,7 +40,6 @@
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/accept_visitor.hh>
 #include <paludis/util/indirect_iterator-impl.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 
 #include <algorithm>
@@ -131,7 +130,7 @@ TEST(InstalledRepository, Metadata)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("cat-one/foo:0",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin());
+                        &env, { }), nullptr, { }))]->begin());
 
     EXPECT_EQ(id1->version(), VersionSpec("1", { }));
     EXPECT_EQ("0", id1->slot_key()->parse_value().raw_value());
@@ -148,7 +147,7 @@ TEST(InstalledRepository, Metadata)
 
     const std::shared_ptr<const PackageID> id2(*env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("cat-one/foo:1",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin());
+                        &env, { }), nullptr, { }))]->begin());
 
     EXPECT_EQ(id2->version(), VersionSpec("2", { }));
     EXPECT_EQ("1", id2->slot_key()->parse_value().raw_value());
@@ -178,13 +177,13 @@ TEST(InstalledRepository, Masks)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("cat-one/foo:0",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin());
+                        &env, { }), nullptr, { }))]->begin());
 
     EXPECT_TRUE(! id1->masked());
 
     const std::shared_ptr<const PackageID> id2(*env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("cat-one/foo:1",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin());
+                        &env, { }), nullptr, { }))]->begin());
 
     EXPECT_TRUE(! id2->masked());
 }
@@ -209,7 +208,7 @@ TEST(InstalledRepository, Actions)
 
     const std::shared_ptr<const PackageID> id1(*env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("cat-one/foo:1",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin());
+                        &env, { }), nullptr, { }))]->begin());
 
     EXPECT_TRUE(! id1->supports_action(SupportsActionTest<InstallAction>()));
     EXPECT_TRUE(! id1->supports_action(SupportsActionTest<ConfigAction>()));
@@ -245,11 +244,11 @@ TEST(InstalledRepository, UninstallLast)
 
     UninstallAction action(make_named_values<UninstallActionOptions>(
                 n::config_protect() = "",
-                n::if_for_install_id() = make_null_shared_ptr(),
+                n::if_for_install_id() = nullptr,
                 n::ignore_for_unmerge() = &ignore_nothing,
                 n::is_overwrite() = false,
                 n::make_output_manager() = &make_standard_output_manager,
-                n::override_contents() = make_null_shared_ptr(),
+                n::override_contents() = nullptr,
                 n::want_phase() = &want_all_phases
             ));
     id->perform_action(action);
@@ -289,15 +288,15 @@ TEST(InstalledRepository, UninstallNotLast)
 
     const std::shared_ptr<const PackageID> id(*env[selection::RequireExactlyOne(
                 generator::Matches(parse_user_package_dep_spec("cat-one/foo:fred",
-                        &env, { }), make_null_shared_ptr(), { }))]->begin());
+                        &env, { }), nullptr, { }))]->begin());
 
     UninstallAction action(make_named_values<UninstallActionOptions>(
                 n::config_protect() = "",
-                n::if_for_install_id() = make_null_shared_ptr(),
+                n::if_for_install_id() = nullptr,
                 n::ignore_for_unmerge() = &ignore_nothing,
                 n::is_overwrite() = false,
                 n::make_output_manager() = &make_standard_output_manager,
-                n::override_contents() = make_null_shared_ptr(),
+                n::override_contents() = nullptr,
                 n::want_phase() = &want_all_phases
             ));
     id->perform_action(action);
@@ -529,16 +528,16 @@ TEST(InstalledRepository, MultipleOps)
 
         UninstallAction action(make_named_values<UninstallActionOptions>(
                     n::config_protect() = "",
-                    n::if_for_install_id() = make_null_shared_ptr(),
+                    n::if_for_install_id() = nullptr,
                     n::ignore_for_unmerge() = &ignore_nothing,
                     n::is_overwrite() = false,
                     n::make_output_manager() = &make_standard_output_manager,
-                    n::override_contents() = make_null_shared_ptr(),
+                    n::override_contents() = nullptr,
                     n::want_phase() = &want_all_phases
                 ));
         (*env[selection::RequireExactlyOne(generator::Matches(
                 parse_user_package_dep_spec("cat/pkg4a",
-                    &env, { }), make_null_shared_ptr(), { }))]->begin())->perform_action(action);
+                    &env, { }), nullptr, { }))]->begin())->perform_action(action);
 
         EXPECT_TRUE(FSPath("installed_repository_TEST_dir/root4/dir").stat().is_directory());
         EXPECT_TRUE(! FSPath("installed_repository_TEST_dir/root4/dir/4a").stat().is_regular_file());
@@ -575,16 +574,16 @@ TEST(InstalledRepository, MultipleOps)
 
         UninstallAction action(make_named_values<UninstallActionOptions>(
                     n::config_protect() = "",
-                    n::if_for_install_id() = make_null_shared_ptr(),
+                    n::if_for_install_id() = nullptr,
                     n::ignore_for_unmerge() = &ignore_nothing,
                     n::is_overwrite() = false,
                     n::make_output_manager() = &make_standard_output_manager,
-                    n::override_contents() = make_null_shared_ptr(),
+                    n::override_contents() = nullptr,
                     n::want_phase() = &want_all_phases
                 ));
         (*env[selection::RequireExactlyOne(generator::Matches(
                 parse_user_package_dep_spec("cat/pkg4b",
-                    &env, { }), make_null_shared_ptr(), { }))]->begin())->perform_action(action);
+                    &env, { }), nullptr, { }))]->begin())->perform_action(action);
 
         EXPECT_TRUE(! FSPath("installed_repository_TEST_dir/root4/dir").stat().is_directory());
 
diff --git a/paludis/repositories/unpackaged/unpackaged_id.cc b/paludis/repositories/unpackaged/unpackaged_id.cc
index 7d02ec851..80cfec97e 100644
--- a/paludis/repositories/unpackaged/unpackaged_id.cc
+++ b/paludis/repositories/unpackaged/unpackaged_id.cc
@@ -28,7 +28,6 @@
 #include <paludis/util/hashes.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/return_literal_function.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/util/singleton-impl.hh>
 #include <paludis/util/timestamp.hh>
@@ -114,9 +113,9 @@ namespace paludis
                         UnpackagedIDData::get_instance()->run_dependencies_labels, r)),
             description_key(std::make_shared<LiteralMetadataValueKey<std::string> >("description", "Description", mkt_significant, d)),
             choices_key(std::make_shared<UnpackagedChoicesKey>(env, "choices", "Choices", mkt_normal, id)),
-            strip_key(ds.is_indeterminate() ? make_null_shared_ptr() :
+            strip_key(ds.is_indeterminate() ? nullptr :
                     std::make_shared<LiteralMetadataValueKey<bool>>("strip", "Strip", mkt_internal, ds.is_true() ? true : false)),
-            preserve_work_key(dw.is_indeterminate() ? make_null_shared_ptr() :
+            preserve_work_key(dw.is_indeterminate() ? nullptr :
                     std::make_shared<LiteralMetadataValueKey<bool>>("preserve_work", "Preserve work", mkt_internal, dw.is_true() ? true : false))
         {
         }
@@ -216,7 +215,7 @@ UnpackagedID::keywords_key() const
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
 UnpackagedID::dependencies_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataSpecTreeKey<DependencySpecTree> >
@@ -288,7 +287,7 @@ UnpackagedID::slot_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 UnpackagedID::behaviours_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataValueKey<bool> >
@@ -415,7 +414,7 @@ UnpackagedID::perform_action(Action & action) const
                 | extra_merger_options,
                 n::output_manager() = output_manager,
                 n::package_id() = shared_from_this(),
-                n::parts() = make_null_shared_ptr(),
+                n::parts() = nullptr,
                 n::perform_uninstall() = install_action->options.perform_uninstall(),
                 n::permit_destination() = std::bind(return_literal_function(true)),
                 n::replacing() = install_action->options.replacing(),
@@ -475,7 +474,7 @@ UnpackagedID::perform_action(Action & action) const
                     n::ignore_for_unmerge() = &ignore_nothing,
                     n::is_overwrite() = false,
                     n::make_output_manager() = std::bind(&this_output_manager, output_manager, std::placeholders::_1),
-                    n::override_contents() = make_null_shared_ptr(),
+                    n::override_contents() = nullptr,
                     n::want_phase() = install_action->options.want_phase()
                     ));
         install_action->options.perform_uninstall()(*i, uo);
@@ -513,6 +512,6 @@ UnpackagedID::choices_key() const
 const std::shared_ptr<const Contents>
 UnpackagedID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/unpackaged/unpackaged_repository.cc b/paludis/repositories/unpackaged/unpackaged_repository.cc
index a829cf187..e656f216d 100644
--- a/paludis/repositories/unpackaged/unpackaged_repository.cc
+++ b/paludis/repositories/unpackaged/unpackaged_repository.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/stringify.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/destringify.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/package_id.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/action.hh>
@@ -309,12 +308,12 @@ UnpackagedRepository::sync(
 const std::shared_ptr<const MetadataCollectionKey<Map<std::string, std::string> > >
 UnpackagedRepository::sync_host_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const Set<std::string> >
 UnpackagedRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
diff --git a/paludis/repositories/unwritten/unwritten_id.cc b/paludis/repositories/unwritten/unwritten_id.cc
index 2702f6fc8..fb5e6758a 100644
--- a/paludis/repositories/unwritten/unwritten_id.cc
+++ b/paludis/repositories/unwritten/unwritten_id.cc
@@ -24,7 +24,6 @@
 #include <paludis/util/visitor_cast.hh>
 #include <paludis/util/set.hh>
 #include <paludis/util/hashes.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/name.hh>
 #include <paludis/version_spec.hh>
 #include <paludis/metadata_key.hh>
@@ -214,7 +213,7 @@ UnwrittenID::fs_location_key() const
 const std::shared_ptr<const MetadataCollectionKey<Set<std::string> > >
 UnwrittenID::behaviours_key() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 const std::shared_ptr<const MetadataCollectionKey<KeywordNameSet> >
@@ -298,7 +297,7 @@ UnwrittenID::choices_key() const
 const std::shared_ptr<const Contents>
 UnwrittenID::contents() const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis
diff --git a/paludis/repositories/unwritten/unwritten_repository.cc b/paludis/repositories/unwritten/unwritten_repository.cc
index 648f6965d..63a219926 100644
--- a/paludis/repositories/unwritten/unwritten_repository.cc
+++ b/paludis/repositories/unwritten/unwritten_repository.cc
@@ -26,7 +26,6 @@
 #include <paludis/util/tokeniser.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/extract_host_from_url.hh>
-#include <paludis/util/make_null_shared_ptr.hh>
 #include <paludis/util/fs_stat.hh>
 #include <paludis/literal_metadata_key.hh>
 #include <paludis/action.hh>
@@ -416,7 +415,7 @@ UnwrittenRepository::sync_host_key() const
 const std::shared_ptr<const Set<std::string> >
 UnwrittenRepository::maybe_expand_licence_nonrecursively(const std::string &) const
 {
-    return make_null_shared_ptr();
+    return nullptr;
 }
 
 namespace paludis