Updated test VM to reduce build time

This change also removes GNOME Circle apps from the test VM.

Author: Thesola10

flake.lock

@@ -1,29 +1,50 @@
 { description = "Tiled, scrollable window management for GNOME Shell";
 
-  inputs."nixpkgs".url = github:NixOS/nixpkgs/gnome;
+  inputs."nixpkgs".url = github:NixOS/nixpkgs;
+  inputs."nixpkgs-gnome".url = github:NixOS/nixpkgs/gnome;
 
-  outputs = { self, nixpkgs, flake-utils, ... }:
+  outputs = { self, nixpkgs, nixpkgs-gnome, flake-utils, ... }:
   flake-utils.lib.eachDefaultSystem
     (system:
-    let pkgs = import nixpkgs { inherit system; };
+    let hostPkgs = import nixpkgs { inherit system; };
     in
-    { packages.default = pkgs.callPackage ./default.nix {};
-      packages.vm = let hostConfig = self.nixosConfigurations.testbox.config;
-                        localConfig = hostConfig // {
-                          virtualisation = hostConfig.virtualisation // {
-                            host.pkgs = pkgs;   # Use host system's Qemu
-                          };
+    { packages.default = hostPkgs.callPackage ./default.nix {};
+
+      # This allows us to build Qemu for the host system thus avoiding
+      # double emulation.
+      packages.vm = let hostConfig = self.nixosConfigurations.testbox;
+                        localConfig = hostConfig.extendModules {
+                          modules = [
+                            ({ modulesPath, ... }: {
+                              imports = [ "${modulesPath}/virtualisation/qemu-vm.nix" ];
+                              virtualisation.host.pkgs = hostPkgs;
+                            })
+                          ];
                         };
-                     in localConfig.system.build.vm;
+                     in localConfig.config.system.build.vm;
     }) // {
       nixosConfigurations."testbox" =
         let system = "x86_64-linux";
+            pkgs-gnome = import nixpkgs-gnome { inherit system; };
         in nixpkgs.lib.nixosSystem {
           inherit system;
           modules = [
             ./vm.nix
             { nixpkgs.overlays = [
+                # Introduce PaperWM into our extensions
                 (s: super: { paperwm = self.packages.${system}.default; })
+
+                # Pull GNOME-specific packages from GNOME staging
+                (s: super: {
+                  gnome         = pkgs-gnome.gnome;
+                  gnome-desktop = pkgs-gnome.gnome-desktop;
+                  gnome-shell   = pkgs-gnome.gnome-shell;
+                  gnome-session = pkgs-gnome.gnome-session;
+                  gnome-control-center = pkgs-gnome.gnome-control-center;
+                  gnome-settings-daemon = pkgs-gnome.gnome-settings-daemon;
+                  mutter        = pkgs-gnome.mutter;
+                  gdm           = pkgs-gnome.gdm;
+                })
               ];
             }
           ];

flake.nix

@@ -27,10 +27,15 @@
           { enabled-extensions = [ "[email protected]" ];
           };
         };
+        #NOTE: You can add more dconf settings to test with here!
       }
     ];
   };
 
+  ### Remove unnecessary dependencies
+  #NOTE: This drops many GTK4 apps, re-enable if needed for testing.
+  services.gnome.core-utilities.enable = false;
+
   ### Set default user
   users.users."user" =
   { isNormalUser = true;