test

lib/default.nix

@@ -52,11 +52,17 @@
       hostPlatform = system;
     };
 
-    pkgs-unstable = import inputs.nixpkgs-unstable { 
+    add-unstable-packages = final: _prev: {
+      unstable = import nixpkgs-unstable {
       inherit system; 
       config.allowUnfree = unfree; 
       hostPlatform = system;
       };
+    };
+
+    nixpkgs.overlays = [
+      add-unstable-packages
+    ];
 
     modules = [
       # Types are 'default', 'small', and 'minimal'

nixos/users/albert/desktop.nix

@@ -1,11 +1,11 @@
-{ config, lib, pkgs, unstable-pkgs, desktop, inputs, system, ... }: {
+{ config, lib, pkgs, unstable, desktop, inputs, system, ... }: {
   # Steam, Vintage Story areu nfree.
   environment.systemPackages = [
     pkgs.bitwarden
     pkgs.steam
     pkgs.lutris
     pkgs.vlc
-    unstable-pkgs.vintagestory
+    unstable.vintagestory
   ];
 
 programs.steam = {