nix compatibility stuff

default.nix

@@ -31,9 +31,12 @@ in {
     settings = {
       experimental-features = [ "nix-command" "flakes" ];
       auto-optimise-store = true;
-      substituters = ["https://nix-community.cachix.org"];
+      keep-outputs = true;
+      keep-derivations = true;
+      substituters = [ "https://nix-community.cachix.org" "https://nixpkgs-wayland.cachix.org" ];
       trusted-public-keys = [
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+        "nixpkgs-wayland.cachix.org-1:3lwxaILxMRkVhehr5StQprHdEo4IrE8sRho9R9HOLYA="
       ];
     };
   };

modules/nix.nix

@@ -0,0 +1,76 @@
+{ lib, pkgs, inputs, config, ... }:
+let
+  nixpkgs = inputs.nixpkgs;
+in {
+  nix.registry.nixpkgs = {
+    from = {
+      id = "nixpkgs";
+      type = "indirect";
+    };
+    to = lib.mkForce {
+      path = "${nixpkgs}";
+      type = "path";
+    };
+  };
+
+  systemd.tmpfiles.rules = [
+    "d   /root/.nix-defexpr        0755  root  root  -  -"
+    "L+  /root/.nix-defexpr/nixos     -     -        -  -  ${nixpkgs}"
+    "L+  /root/.nix-defexpr/nixpkgs   -     -        -  -  ${nixpkgs}"
+  ];
+
+  # Provide compatibility layer for non-flake utils
+  environment.etc."nixos/compat/default.nix".text = ''
+    { ... }:
+
+    let
+      nixpkgs = import ${nixpkgs} {};
+    in
+    nixpkgs
+  '';
+
+  environment.etc."nixos/compat/nixos/default.nix".text = ''
+    { ... }:
+
+    let
+      current = import ${inputs.self};
+    in
+    current.nixosConfigurations."${config.networking.hostName}"
+  '';
+
+  environment.etc."nixos/configuration.nix".text = ''
+    nix = {
+      nixPath = [ "nixpkgs=${nixpkgs}" ];
+    };
+
+    system.name = "${config.networking.hostName}";
+    system.stateVersion = "${config.system.stateVersion}";
+  '';
+
+  environment.etc."nixos/current".source = inputs.self;
+  environment.etc."nixos/nixpkgs".source = nixpkgs;
+  environment.etc."nixos/options.json".source =
+    if config.documentation.nixos.enable
+    then "${config.system.build.manual.optionsJSON}/share/doc/nixos/options.json"
+    else
+      pkgs.writeTextFile {
+        name = "options.json";
+        text = "{}";
+      };
+
+  environment.etc."nixos/system-packages".text =
+    let
+      packages = builtins.map (p: "${p.name}") config.environment.systemPackages;
+      sorted = builtins.sort (a: b: lib.toLower a < lib.toLower b) (lib.unique packages);
+      formatted = builtins.concatStringsSep "\n" sorted;
+    in
+    formatted;
+
+  environment.extraInit = ''
+    export NIX_PATH="nixpkgs=${nixpkgs}"
+  '';
+
+  environment.systemPackages = with pkgs; [
+    nixos-option
+  ];
+}