fix: agenix on nix-darwin, update flake.nix

modules/base.nix

@@ -29,25 +29,6 @@
     builders-use-substitutes = true;
   };
 
-  # do garbage collection weekly to keep disk usage low
-  nix.gc =
-    {
-      automatic = lib.mkDefault true;
-      options = lib.mkDefault "--delete-older-than 7d";
-    }
-    // (
-      if pkgs.stdenv.isLinux
-      then {
-        dates = lib.mkDefault "weekly";
-      }
-      else {
-        # nix-darwin
-        interval = {
-          Hour = 24;
-        };
-      }
-    );
-
   # Allow unfree packages
   nixpkgs.config.allowUnfree = lib.mkDefault false;
 }

modules/darwin/nix-core.nix

@@ -1,6 +1,5 @@
 {
   pkgs,
-  lib,
   ...
 }: {
   ###################################################################################
@@ -27,7 +26,7 @@
   # Disable auto-optimise-store because of this issue:
   #   https://github.com/NixOS/nix/issues/7273
   # "error: cannot link '/nix/store/.tmp-link-xxxxx-xxxxx' to '/nix/store/.links/xxxx': File exists"
-  nix.settings = {
-    auto-optimise-store = false;
-  };
+  nix.settings.auto-optimise-store = false;
+
+  nix.gc.automatic = false;
 }

modules/nixos/base/misc.nix

@@ -15,6 +15,13 @@
   # for nix server, we do not need to keep too much generations
   boot.loader.systemd-boot.configurationLimit = lib.mkDefault 10;
 
+  # do garbage collection weekly to keep disk usage low
+  nix.gc = {
+    automatic = lib.mkDefault true;
+    dates = lib.mkDefault "weekly";
+    options = lib.mkDefault "--delete-older-than 7d";
+  };
+
   # Manual optimise storage: nix-store --optimise
   # https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-auto-optimise-store
   nix.settings.auto-optimise-store = true;