flake.nix: force garnix to build darwin configs

flake.nix

@@ -25,6 +25,7 @@
           self',
           pkgs,
           lib,
+          system,
           ...
         }:
         {
@@ -37,7 +38,21 @@
             ];
           };
 
-          packages.base-packages = pkgs.symlinkJoin {
+          packages =
+            let
+              darwinConfigs = lib.filterAttrs (
+                _: config: config.eval.config.nixpkgs.system == system
+              ) inputs.self.darwinConfigurations;
+              # Force garnix to build the config
+              darwinConfigs' = lib.mapAttrs' (name: config: {
+                name = "__darwinConfigurations_${name}";
+                value = config.system;
+              }) darwinConfigs;
+            in
+            {
+              # Re-export it for convenience and for caching
+              inherit (inputs'.attic.packages) attic-client attic-server;
+              base-packages = pkgs.symlinkJoin {
                 name = "settei-base";
                 paths = with self'.packages; [
                   helix
@@ -45,10 +60,8 @@
                   git-commit-last
                 ];
               };
-          # Re-export it for convenience and for caching
+            }
-          packages = {
+            // darwinConfigs';
-            inherit (inputs'.attic.packages) attic-client attic-server;
-          };
 
           formatter = pkgs.nixfmt-rfc-style;
         };