Fix the makeServiceConfig function.

flake.nix

@@ -100,12 +100,11 @@
       };
     in
     {
-      systemConfig = self.lib.makeServiceConfig {
+      systemConfig = self.lib.makeSystemConfig {
         inherit system;
         modules = [
           ./nix/modules
         ];
-        inherit (self.packages.${system}) system-manager;
       };
 
       packages = {
@@ -184,6 +183,8 @@
     }))
     //
     {
-      lib = import ./nix/lib.nix { inherit nixpkgs; };
+      lib = import ./nix/lib.nix {
+        inherit nixpkgs self;
+      };
     };
 }

nix/lib.nix

@@ -1,21 +1,25 @@
-{ nixpkgs }:
+{ nixpkgs
+, self
+,
+}:
 let
   inherit (nixpkgs) lib;
 in
 {
-  makeServiceConfig =
+  makeSystemConfig =
     { system
     , modules
-    , system-manager
+    , extraSpecialArgs ? { }
     ,
     }:
     let
       pkgs = nixpkgs.legacyPackages.${system};
+      inherit (self.packages.${system}) system-manager;
 
       nixosConfig = (lib.nixosSystem {
         inherit system;
         modules = [ ./modules/system-manager.nix ] ++ modules;
-        specialArgs = { };
+        specialArgs = extraSpecialArgs;
       }).config;
 
       returnIfNoAssertions = drv:
@@ -84,7 +88,6 @@ in
         text = lib.generators.toJSON { } etcFiles;
       };
 
-      # TODO: remove --ephemeral
       activationScript = pkgs.writeShellScript "activate" ''
         ${system-manager}/bin/system-manager activate \
           --store-path "$(realpath $(dirname ''${0}))" \