General: Use overlay for unstable packages

flake.lock

@@ -234,11 +234,11 @@
     "nix-secrets": {
       "flake": false,
       "locked": {
-        "lastModified": 1723838364,
+        "lastModified": 1724432746,
-        "narHash": "sha256-L1KajQACN1256oVG//QPXWuVbuzxlSAlOjXT67i6c0Q=",
+        "narHash": "sha256-s7XsY4ZsS9jyzZWpXOJNVzc03SNQbALM+S28QKXc8co=",
         "ref": "refs/heads/main",
-        "rev": "d57c296dab0ec1e7c6f28c7741d9a591b35117da",
+        "rev": "56ccf5bf3f4d8687dc22c390cdafe20c08a7e549",
-        "revCount": 59,
+        "revCount": 60,
         "type": "git",
         "url": "file:./nix-secrets"
       },

flake.nix

@@ -87,19 +87,11 @@
     in
     {
       formatter = forAllSystems (pkgs: pkgs.nixfmt-rfc-style);
+
       nixosConfigurations = {
 
         Dimaga = nixpkgs.lib.nixosSystem {
           system = "x86_64-linux";
-
-          # Add unstable repo
-          specialArgs = {
-            pkgs-unstable = import nixpkgs-unstable {
-              system = "x86_64-linux";
-              config.allowUnfree = true;
-            };
-          };
-
           modules = defaultModules ++ [
             nixos-hardware.nixosModules.common-cpu-intel
             ./hosts/Dimaga

modules/common.nix

@@ -1,5 +1,10 @@
 # Modules common to all systems
-{ pkgs, config, ... }:
+{
+  pkgs,
+  config,
+  inputs,
+  ...
+}:
 
 {
   config = {
@@ -14,6 +19,16 @@
       ];
     };
 
+    # Allow packages from the unstable repo by using 'pkgs.unstable'
+    nixpkgs.overlays = [
+      (final: _prev: {
+        unstable = import inputs.nixpkgs-unstable {
+          system = final.system;
+          config.allowUnfree = true;
+        };
+      })
+    ];
+
     programs = {
       # Enable NH, an alternative nixos-rebuild frontend.
       nh = {