Install darwin-uninstall by default, which includes the 'empty' config it switches to

Co-Authored-By: Michael Hoang <enzime@users.noreply.github.com>

default.nix

@@ -16,7 +16,7 @@ let
     };
   };
 
-  # The source code of this repo needed by the [un]installers.
+  # The source code of this repo needed by the installer.
   nix-darwin = lib.cleanSource (
     lib.cleanSourceWith {
       # We explicitly specify a name here otherwise `cleanSource` will use the
@@ -30,5 +30,5 @@ in
 
 eval // {
   installer = pkgs.callPackage ./pkgs/darwin-installer { inherit nix-darwin; };
-  uninstaller = pkgs.callPackage ./pkgs/darwin-uninstaller { inherit nix-darwin; };
+  uninstaller = pkgs.callPackage ./pkgs/darwin-uninstaller { };
 }

flake.nix

@@ -42,7 +42,7 @@
     overlays.default = final: prev: {
       inherit (prev.callPackage ./pkgs/nix-tools { }) darwin-rebuild darwin-option darwin-version;
 
-      darwin-uninstaller = prev.callPackage ./pkgs/darwin-uninstaller { nix-darwin = self; };
+      darwin-uninstaller = prev.callPackage ./pkgs/darwin-uninstaller { };
     };
 
     darwinModules.hydra = ./modules/examples/hydra.nix;

modules/nix/nix-darwin.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, ... }:
+{ config, pkgs, lib, ... }:
 
 let
   nix-tools = pkgs.callPackage ../../pkgs/nix-tools {
@@ -7,22 +7,30 @@ let
     nixPackage = config.nix.package;
   };
 
+  darwin-uninstaller = pkgs.callPackage ../../pkgs/darwin-uninstaller { };
+
   inherit (nix-tools) darwin-option darwin-rebuild darwin-version;
 in
 
 {
-  config = {
+  options = {
+    system.includeUninstaller = lib.mkOption {
+      type = lib.types.bool;
+      internal = true;
+      default = true;
+    };
+  };
 
+  config = {
     environment.systemPackages =
       [ # Include nix-tools by default
         darwin-option
         darwin-rebuild
         darwin-version
-      ];
+      ] ++ lib.optional config.system.includeUninstaller darwin-uninstaller;
 
     system.build = {
       inherit darwin-option darwin-rebuild darwin-version;
     };
-
   };
 }

pkgs/darwin-uninstaller/configuration.nix

@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ lib, ... }:
 
 with lib;
 

pkgs/darwin-uninstaller/default.nix

@@ -1,18 +1,17 @@
-{ stdenv, nix, pkgs, nix-darwin }:
+{ stdenv, lib, pkgs }:
 
 let
-  configuration = builtins.path {
-    name = "nix-darwin-uninstaller-configuration";
-    path = ./.;
-    filter = name: _type: name != toString ./default.nix;
+  uninstallSystem = import ../../eval-config.nix {
+    inherit lib;
+    modules = [
+      ./configuration.nix
+      {
+        nixpkgs.source = pkgs.path;
+        nixpkgs.hostPlatform = pkgs.system;
+        system.includeUninstaller = false;
+      }
+    ];
   };
-
-  nixPath = pkgs.lib.concatStringsSep ":" [
-    "darwin-config=${configuration}/configuration.nix"
-    "darwin=${nix-darwin}"
-    "nixpkgs=${pkgs.path}"
-    "$NIX_PATH"
-  ];
 in
 
 stdenv.mkDerivation {
@@ -62,10 +61,7 @@ stdenv.mkDerivation {
         esac
     fi
 
-    export nix=${nix}
-    export NIX_PATH=${nixPath}
-    system=$($nix/bin/nix-build '<darwin>' -A system)
-    $system/sw/bin/darwin-rebuild switch
+    ${uninstallSystem.system}/sw/bin/darwin-rebuild activate
 
     if test -L /run/current-system; then
       sudo rm /run/current-system