cleaned up nix settings

modules/nix.nix

@@ -1,5 +1,24 @@
-inputs: {pkgs, ...}: {
+inputs: {
-  #other nix settings
+  pkgs,
+  lib,
+  ...
+}:
+#
+# Flake registry and $NIX_PATH pinning
+#
+let
+  alias = inputs // {nixpkgs = inputs.unstable;};
+  flakes = lib.filterAttrs (_: v: v._type == "flake") alias;
+in {
+  nix.nixPath = lib.mapAttrsToList (x: _: "${x}=flake:${x}") flakes;
+  nix.registry = lib.mapAttrs (_: flake: {inherit flake;}) flakes;
+  #
+  # Ignore global registry
+  #
+  nix.settings.flake-registry = builtins.toFile "empty-flake-registry.json" ''{"flakes":[],"version":2}'';
+  #
+  # Other nix settings
+  #
   nix = {
     package = inputs.nix.packages.${pkgs.system}.default;
     settings = {
@@ -10,8 +29,6 @@ inputs: {pkgs, ...}: {
       ];
       auto-optimise-store = true;
       warn-dirty = false;
-      #ignore global registry
-      flake-registry = builtins.toFile "empty-flake-registry.json" ''{"flakes":[],"version":2}'';
       #use for testing
       #allow-import-from-derivation = false;
       trusted-users = [
@@ -22,6 +39,7 @@ inputs: {pkgs, ...}: {
       use-xdg-base-directories = true;
     };
   };
+
   #fix for use-xdg-base-directories
   environment.profiles = [
     "\${XDG_STATE_HOME:-$HOME/.local/state}/nix/profile"

modules/pinning.nix

@@ -1,11 +0,0 @@
-inputs: {lib, ...}: let
-  alias = inputs // {nixpkgs = inputs.unstable;};
-in
-  lib.pipe alias [
-    (lib.filterAttrs (_: v: v._type == "flake"))
-    (lib.mapAttrsToList (n: input: {
-      nix.nixPath = ["${n}=flake:${n}"];
-      nix.registry.${n}.flake = input;
-    }))
-    lib.mkMerge
-  ]