diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c03bc931..5f0fddb9 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -119,28 +119,18 @@ jobs:
       uses: cachix/install-nix-action@v22
       with:
         install_url: https://github.com/nix-community/nix-unstable-installer/releases/download/nix-2.10.0pre20220822_7c3ab57/install
-        nix_path: nixpkgs=channel:${{ env.CURRENT_STABLE_CHANNEL }}
         extra_nix_config: |
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-    - name: Install ${{ env.CURRENT_STABLE_CHANNEL }} channel
+    - name: Install nix-darwin
       run: |
-        nix-channel --add https://nixos.org/channels/${{ env.CURRENT_STABLE_CHANNEL }} nixpkgs
-        nix-channel --update
-    - name: Install nix-darwin and test result
-      run: |
-        export NIX_PATH=$HOME/.nix-defexpr/channels
-        nix-shell -A installer
-        nix-shell -A installer.check
-    - name: Build simple flake configuration
-      run: |
-        nix build ./modules/examples/flake#darwinConfigurations.simple.system --override-input darwin .
-    - name: Activate derivation of simple flake build
-      run: |
-        ./result/sw/bin/darwin-rebuild switch --flake ./modules/examples/flake#simple --override-input darwin .
-    - name: Rebuild and activate simple flake, but this time using nix-darwins flake interface
+        nix run .#darwin-rebuild -- \
+          switch --flake ./modules/examples/flake#simple \
+          --override-input darwin . \
+          --override-input nixpkgs nixpkgs/${{ env.CURRENT_STABLE_CHANNEL }}
+    - name: Rebuild and activate simple flake, but this time using nix-darwin's flake interface
       run: |
         . /etc/static/bashrc
-        darwin-rebuild build --flake ./modules/examples/flake#simple --override-input darwin .
+        darwin-rebuild build --flake ./modules/examples/flake#simple --override-input darwin . --override-input nixpkgs nixpkgs/${{ env.CURRENT_STABLE_CHANNEL }}
     - name: Test git submodules
       run: |
         . /etc/static/bashrc
@@ -175,6 +165,7 @@ jobs:
         darwin-rebuild build \
           --flake /tmp/test-nix-darwin-submodules#simple \
           --override-input darwin . \
+          --override-input nixpkgs nixpkgs/${{ env.CURRENT_STABLE_CHANNEL }} \
           && {
             printf 'succeeded while expecting failure due to submodule\n' >/dev/stderr
             exit 1
@@ -183,6 +174,7 @@ jobs:
         darwin-rebuild build \
           --flake /tmp/test-nix-darwin-submodules?submodules=0#simple \
           --override-input darwin . \
+          --override-input nixpkgs nixpkgs/${{ env.CURRENT_STABLE_CHANNEL }} \
           && {
             printf 'succeeded while expecting failure due to submodule\n' >/dev/stderr
             exit 1
@@ -191,7 +183,8 @@ jobs:
         # Should succeed
         darwin-rebuild build \
           --flake /tmp/test-nix-darwin-submodules?submodules=1#simple \
-          --override-input darwin .
+          --override-input darwin . \
+          --override-input nixpkgs nixpkgs/${{ env.CURRENT_STABLE_CHANNEL }} \
 
   install-flake-against-unstable:
     runs-on: macos-12
@@ -201,28 +194,18 @@ jobs:
     - name: Install nix from current unstable channel
       uses: cachix/install-nix-action@v22
       with:
-        nix_path: nixpkgs=channel:nixpkgs-unstable
         extra_nix_config: |
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-    - name: Install nixpkgs-unstable channel
+    - name: Install nix-darwin
       run: |
-        nix-channel --add https://nixos.org/channels/nixpkgs-unstable nixpkgs
-        nix-channel --update
-    - name: Install nix-darwin and test result
-      run: |
-        export NIX_PATH=$HOME/.nix-defexpr/channels
-        nix-shell -A installer
-        nix-shell -A installer.check
-    - name: Build simple flake configuration
-      run: |
-        nix build ./modules/examples/flake#darwinConfigurations.simple.system --override-input darwin .
-    - name: Activate derivation of simple flake build
-      run: |
-        ./result/sw/bin/darwin-rebuild switch --flake ./modules/examples/flake#simple --override-input darwin .
-    - name: Rebuild and activate simple flake, but this time using nix-darwins flake interface
+        nix run .#darwin-rebuild -- \
+          switch --flake ./modules/examples/flake#simple \
+          --override-input darwin . \
+          --override-input nixpkgs nixpkgs/nixpkgs-unstable
+    - name: Rebuild and activate simple flake, but this time using nix-darwin's flake interface
       run: |
         . /etc/static/bashrc
-        darwin-rebuild build --flake ./modules/examples/flake#simple --override-input darwin .
+        darwin-rebuild build --flake ./modules/examples/flake#simple --override-input darwin . --override-input nixpkgs nixpkgs/nixpkgs-unstable
     - name: Test git submodules
       run: |
         . /etc/static/bashrc
@@ -257,14 +240,17 @@ jobs:
         darwin-rebuild build \
           --flake /tmp/test-nix-darwin-submodules#simple \
           --override-input darwin . \
+          --override-input nixpkgs nixpkgs/nixpkgs-unstable \
           && {
             printf 'succeeded while expecting failure due to submodule\n' >/dev/stderr
             exit 1
           }
+
         # Should also fail
         darwin-rebuild build \
           --flake /tmp/test-nix-darwin-submodules?submodules=0#simple \
           --override-input darwin . \
+          --override-input nixpkgs nixpkgs/nixpkgs-unstable \
           && {
             printf 'succeeded while expecting failure due to submodule\n' >/dev/stderr
             exit 1
@@ -273,8 +259,11 @@ jobs:
         # Should succeed
         darwin-rebuild build \
           --flake /tmp/test-nix-darwin-submodules?submodules=1#simple \
-          --override-input darwin .
+          --override-input darwin . \
+          --override-input nixpkgs nixpkgs/nixpkgs-unstable
+
         # Should also succeed
         darwin-rebuild build \
           --flake git+file:///tmp/test-nix-darwin-submodules?submodules=1#simple \
-          --override-input darwin .
+          --override-input darwin . \
+          --override-input nixpkgs nixpkgs/nixpkgs-unstable
diff --git a/README.md b/README.md
index d31d6c8d..2fd79494 100644
--- a/README.md
+++ b/README.md
@@ -123,13 +123,6 @@ nix build ~/.config/darwin\#darwinConfigurations.Johns-MacBook.system
 ## Manual Install
 
 ```bash
-# Before 10.15 Catalina
-sudo ln -s private/var/run /run
-# After 10.15 Catalina
-echo -e "run\tprivate/var/run" | sudo tee -a /etc/synthetic.conf
-/System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B
-/System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t
-
 # Configure the channel
 nix-channel --add https://github.com/LnL7/nix-darwin/archive/master.tar.gz darwin
 nix-channel --update
diff --git a/flake.nix b/flake.nix
index dab4739d..b1808c9d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -36,6 +36,12 @@
           });
     };
 
+    overlays.default = final: prev: {
+      inherit (prev.callPackage ./pkgs/nix-tools { }) darwin-rebuild darwin-option;
+
+      darwin-uninstaller = prev.callPackage ./pkgs/darwin-uninstaller { nix-darwin = self; };
+    };
+
     darwinModules.hydra = ./modules/examples/hydra.nix;
     darwinModules.lnl = ./modules/examples/lnl.nix;
     darwinModules.ofborg = ./modules/examples/ofborg.nix;
@@ -63,20 +69,14 @@
     });
 
     packages = forAllSystems (system: let
-      pkgs = nixpkgs.legacyPackages.${system};
-
-      darwin = self.lib.darwinSystem {
+      pkgs = import nixpkgs {
         inherit system;
-        modules = [ ];
+        overlays = [ self.overlays.default ];
       };
-
-      nix-tools = pkgs.callPackage ./pkgs/nix-tools { inherit darwin; };
     in {
       default = self.packages.${system}.darwin-rebuild;
 
-      inherit (nix-tools) darwin-rebuild darwin-option;
-
-      darwin-uninstaller = pkgs.callPackage ./pkgs/darwin-uninstaller { nix-darwin = self; };
+      inherit (pkgs) darwin-option darwin-rebuild darwin-uninstaller;
     });
   };
 }
diff --git a/modules/module-list.nix b/modules/module-list.nix
index 2844c918..582421b9 100644
--- a/modules/module-list.nix
+++ b/modules/module-list.nix
@@ -8,6 +8,7 @@
   ./security/pki
   ./security/sandbox
   ./system
+  ./system/base.nix
   ./system/checks.nix
   ./system/activation-scripts.nix
   ./system/applications.nix
diff --git a/modules/nix/nix-darwin.nix b/modules/nix/nix-darwin.nix
index a96fdb2f..ee17af26 100644
--- a/modules/nix/nix-darwin.nix
+++ b/modules/nix/nix-darwin.nix
@@ -1,31 +1,13 @@
-{ config, pkgs, lib, ... }:
+{ config, pkgs, ... }:
 
 let
-  inherit (pkgs) stdenv;
+  nix-tools = pkgs.callPackage ../../pkgs/nix-tools {
+    inherit (config.system) profile;
+    inherit (config.environment) systemPath;
+    nixPackage = config.nix.package;
+  };
 
-  extraPath = lib.makeBinPath [ config.nix.package pkgs.coreutils pkgs.jq pkgs.git ];
-
-  writeProgram = name: env: src:
-    pkgs.substituteAll ({
-      inherit name src;
-      dir = "bin";
-      isExecutable = true;
-    } // env);
-
-  darwin-option = writeProgram "darwin-option"
-    {
-      inherit (stdenv) shell;
-      path = "${extraPath}:${config.environment.systemPath}";
-    }
-    ../../pkgs/nix-tools/darwin-option.sh;
-
-  darwin-rebuild = writeProgram "darwin-rebuild"
-    {
-      inherit (config.system) profile;
-      inherit (stdenv) shell;
-      path = "${extraPath}:${config.environment.systemPath}";
-    }
-    ../../pkgs/nix-tools/darwin-rebuild.sh;
+  inherit (nix-tools) darwin-option darwin-rebuild;
 in
 
 {
diff --git a/modules/system/activation-scripts.nix b/modules/system/activation-scripts.nix
index d5ca292b..b92a6928 100644
--- a/modules/system/activation-scripts.nix
+++ b/modules/system/activation-scripts.nix
@@ -69,11 +69,6 @@ in
 
       ${cfg.activationScripts.postActivation.text}
 
-      # Ensure /run exists.
-      if [ ! -e /run ]; then
-        ln -sfn private/var/run /run
-      fi
-
       # Make this configuration the current configuration.
       # The readlink is there to ensure that when $systemConfig = /system
       # (which is a symlink to the store), /run/current-system is still
@@ -102,6 +97,7 @@ in
 
       ${cfg.activationScripts.preUserActivation.text}
 
+      ${cfg.activationScripts.createRun.text}
       ${cfg.activationScripts.checks.text}
       ${cfg.activationScripts.extraUserActivation.text}
       ${cfg.activationScripts.userDefaults.text}
diff --git a/modules/system/base.nix b/modules/system/base.nix
new file mode 100644
index 00000000..44a8d912
--- /dev/null
+++ b/modules/system/base.nix
@@ -0,0 +1,24 @@
+{ ... }:
+
+{
+  system.activationScripts.createRun.text = ''
+    if ! test -L /run; then
+      if ! grep -q '^run\b' /etc/synthetic.conf 2>/dev/null; then
+          echo "setting up /run via /etc/synthetic.conf..."
+          echo -e "run\tprivate/var/run" | sudo tee -a /etc/synthetic.conf >/dev/null
+          sudo /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B &>/dev/null || true
+          sudo /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t &>/dev/null || true
+          if ! test -L /run; then
+            echo "warning: apfs.util failed to symlink /run"
+          fi
+      fi
+      if ! test -L /run; then
+          echo "setting up /run..."
+          sudo ln -sfn private/var/run /run
+      fi
+      if ! test -L /run; then
+        echo "warning: failed to symlink /run"
+      fi
+    fi
+  '';
+}
diff --git a/modules/system/checks.nix b/modules/system/checks.nix
index b1571abb..f90d9a2a 100644
--- a/modules/system/checks.nix
+++ b/modules/system/checks.nix
@@ -28,8 +28,8 @@ let
         if test -e /etc/synthetic.conf; then
             echo >&2
             echo "$ printf 'run\tprivate/var/run\n' | sudo tee -a /etc/synthetic.conf" >&2
-            echo "$ /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B # For Catalina" >&2
-            echo "$ /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t # For Big Sur and later" >&2
+            echo "$ sudo /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B # For Catalina" >&2
+            echo "$ sudo /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t # For Big Sur and later" >&2
             echo >&2
             echo "The current contents of /etc/synthetic.conf is:" >&2
             echo >&2
diff --git a/pkgs/darwin-installer/configuration.nix b/pkgs/darwin-installer/configuration.nix
index a0e58a16..c9ce6603 100644
--- a/pkgs/darwin-installer/configuration.nix
+++ b/pkgs/darwin-installer/configuration.nix
@@ -6,5 +6,4 @@ with lib;
   imports = [ <user-darwin-config> ./installer.nix ];
 
   nix.configureBuildUsers = true;
-  users.knownGroups = [ "nixbld" ];
 }
diff --git a/pkgs/darwin-installer/installer.nix b/pkgs/darwin-installer/installer.nix
index 485441bc..75395db9 100644
--- a/pkgs/darwin-installer/installer.nix
+++ b/pkgs/darwin-installer/installer.nix
@@ -30,31 +30,5 @@ with lib;
                 ;;
         esac
     fi
-
-    if ! test -L /run; then
-      if test -t 1; then
-          read -p "Would you like to create /run? [y/n] " i
-      fi
-      case "$i" in
-          y|Y)
-              if ! grep -q '^run\b' /etc/synthetic.conf 2>/dev/null; then
-                  echo "setting up /run via /etc/synthetic.conf..."
-                  echo -e "run\tprivate/var/run" | sudo tee -a /etc/synthetic.conf >/dev/null
-                  sudo /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B &>/dev/null || true
-                  sudo /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t &>/dev/null || true
-                  if ! test -L /run; then
-                    echo "warning: apfs.util failed to symlink /run"
-                  fi
-              fi
-              if ! test -L /run; then
-                  echo "setting up /run..."
-                  sudo ln -sfn private/var/run /run
-              fi
-              if ! test -L /run; then
-                echo "warning: failed to symlink /run"
-              fi
-              ;;
-      esac
-    fi
   '';
 }
diff --git a/pkgs/nix-tools/default.nix b/pkgs/nix-tools/default.nix
index 93fd3e38..22fcafa9 100644
--- a/pkgs/nix-tools/default.nix
+++ b/pkgs/nix-tools/default.nix
@@ -1,7 +1,38 @@
-{ darwin }:
+{ lib
+, coreutils
+, jq
+, git
+, substituteAll
+, stdenv
+, profile ? "/nix/var/nix/profiles/system"
+, nixPackage ? "/nix/var/nix/profiles/default"
+, systemPath ? "$HOME/.nix-profile/bin:/etc/profiles/per-user/$USER/bin:/run/current-system/sw/bin:/nix/var/nix/profiles/default/bin:/usr/local/bin:/usr/bin:/usr/sbin:/bin:/sbin"
+}:
 
 let
-  inherit (darwin) config;
-in {
-  inherit (config.system.build) darwin-option darwin-rebuild;
+  extraPath = lib.makeBinPath [ nixPackage coreutils jq git ];
+
+  writeProgram = name: env: src:
+    substituteAll ({
+      inherit name src;
+      dir = "bin";
+      isExecutable = true;
+    } // env);
+
+  path = "${extraPath}:${systemPath}";
+in
+{
+  darwin-option = writeProgram "darwin-option"
+    {
+      inherit path;
+      inherit (stdenv) shell;
+    }
+    ./darwin-option.sh;
+
+  darwin-rebuild = writeProgram "darwin-rebuild"
+    {
+      inherit path profile;
+      inherit (stdenv) shell;
+    }
+    ./darwin-rebuild.sh;
 }