nix config changes

sys/profiles/nix/default.nix

@@ -1,34 +1,50 @@
-{
-  config,
-  pkgs,
-  inputs,
-  lib,
-  ...
-}: {
-  imports = [
-    ./substituters.nix
-  ];
-
-  # git is needed for flakes
-  environment.systemPackages = [pkgs.git];
-
+{inputs, ...}: {
   nix = {
-    # pin the registry to avoid downloading and evaling a new nixpkgs version every time
-    registry = lib.mapAttrs (_: v: {flake = v;}) inputs;
+    registry.nixpkgs.to = {
+      type = "github";
+      owner = "NixOS";
+      repo = "nixpkgs";
+      rev = inputs.nixpkgs.rev;
+    };
 
-    # set the path for channels compat
-    nixPath = lib.mapAttrsToList (key: _: "${key}=flake:${key}") config.nix.registry;
+    nixPath = ["nixpkgs=${inputs.nixpkgs.outPath}"];
 
     settings = {
-      #auto-optimise-store = true;
       builders-use-substitutes = true;
-      experimental-features = ["flakes" "nix-command" "pipe-operators" "no-url-literals"];
-
-      # for direnv GC roots
       keep-outputs = true;
       keep-derivations = true;
+      accept-flake-config = true;
+      use-xdg-base-directories = true;
 
-      trusted-users = ["root" "@wheel"];
+      flake-registry = builtins.toFile "none.json" (builtins.toJSON {
+        flakes = [];
+        version = 2;
+      });
+
+      experimental-features = [
+        "flakes"
+        "nix-command"
+        "pipe-operators"
+        "no-url-literals"
+        "ca-derivations"
+      ];
+
+      trusted-users = [
+        "root"
+        "@wheel"
+      ];
+
+      substituters = [
+        "https://cache.nixos.org?priority=10"
+        "https://nix-community.cachix.org?priority=11"
+        "https://nix-gaming.cachix.org?priority=12"
+      ];
+
+      trusted-public-keys = [
+        "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+        "nix-gaming.cachix.org-1:nbjlureqMbRAxR1gJ/f3hxemL9svXaZF/Ees8vCUUs4="
+      ];
     };
   };
 }