nixosModules/clanCore: support nix-darwin

nixosModules/clanCore/defaults.nix

@@ -1,10 +1,27 @@
 {
+  _class,
   lib,
   config,
   pkgs,
   ...
 }:
 {
+  imports = lib.optional (_class == "nixos") (
+    lib.mkIf config.clan.core.enableRecommendedDefaults {
+      # Use systemd during boot as well except:
+      # - systems with raids as this currently require manual configuration: https://github.com/NixOS/nixpkgs/issues/210210
+      # - for containers we currently rely on the `stage-2` init script that sets up our /etc
+      boot.initrd.systemd.enable = lib.mkDefault (!config.boot.swraid.enable && !config.boot.isContainer);
+
+      # Don't install the /lib/ld-linux.so.2 stub. This saves one instance of nixpkgs.
+      environment.ldso32 = null;
+
+      environment.systemPackages = [
+        pkgs.nixos-facter # for `clan machines update-hardware-config --backend nixos-facter`
+      ];
+    }
+  );
+
   options.clan.core.enableRecommendedDefaults = lib.mkOption {
     type = lib.types.bool;
     description = ''
@@ -20,11 +37,6 @@
   };
 
   config = lib.mkIf config.clan.core.enableRecommendedDefaults {
-    # Use systemd during boot as well except:
-    # - systems with raids as this currently require manual configuration: https://github.com/NixOS/nixpkgs/issues/210210
-    # - for containers we currently rely on the `stage-2` init script that sets up our /etc
-    boot.initrd.systemd.enable = lib.mkDefault (!config.boot.swraid.enable && !config.boot.isContainer);
-
     # This disables the HTML manual and `nixos-help` command but leaves
     # `man configuration.nix`
     documentation.doc.enable = lib.mkDefault false;
@@ -32,9 +44,6 @@
     # Work around for https://github.com/NixOS/nixpkgs/issues/124215
     documentation.info.enable = lib.mkDefault false;
 
-    # Don't install the /lib/ld-linux.so.2 stub. This saves one instance of nixpkgs.
-    environment.ldso32 = null;
-
     environment.systemPackages = [
       # essential debugging tools for networked services
       pkgs.dnsutils
@@ -43,8 +52,6 @@
       pkgs.jq
       pkgs.htop
 
-      pkgs.nixos-facter # for `clan machines update-hardware-config --backend nixos-facter`
-
       pkgs.gitMinimal
     ];
   };