cleanup

common/flakes.nix

@@ -1,4 +1,4 @@
-{ lib, pkgs, config, ... }:
+{ lib, pkgs, config, inputs, ... }:
 with lib;
 let
   cfg = config.nix.flakes;
@@ -13,6 +13,9 @@ in {
       extraOptions = ''
         experimental-features = nix-command flakes
       '';
+
+      # pin nixpkgs for system commands such as "nix shell"
+      registry.nixpkgs.flake = inputs.nixpkgs;
     };
   };
 }

flake.nix

@@ -14,11 +14,8 @@
           modules = [
             path
             simple-nixos-mailserver.nixosModule
-            ( { pkgs, ... }: {
-              # pin nixpkgs for system commands such as "nix shell"
-              nix.registry.nixpkgs.flake = nixpkgs;
-            } )
           ];
+          specialArgs = { inherit inputs; };
         };
     in
     {