pass top-level-flake to set system.configurationRevision

flake.nix

@@ -7,7 +7,6 @@
     selfprivacy-graphql-api.url =
       "git+https://git.selfprivacy.org/SelfPrivacy/selfprivacy-rest-api.git";
     selfprivacy-graphql-api.inputs.nixpkgs.follows = "nixpkgs";
-    # TODO nixpkgs inputs of selfprivacy-graphql-api and this flake must match!
   };
 
   outputs = { self, nixpkgs, selfprivacy-graphql-api }:
@@ -15,7 +14,11 @@
       system = "x86_64-linux";
     in
     {
-      nixosConfigurations-fun = { hardware-configuration, userdata }: {
+      nixosConfigurations-fun =
+        { hardware-configuration
+        , userdata
+        , top-level-flake
+        }: {
           just-nixos = nixpkgs.lib.nixosSystem {
             specialArgs = {
               inherit
@@ -28,7 +31,15 @@
             modules = [
               hardware-configuration
               ./configuration.nix
+              {
+                # for running "nix search nixpkgs", etc
+                nix.registry.nixpkgs.flake = nixpkgs;
+                # dirty builds are forbidden
+                system.configurationRevision = top-level-flake.rev; # FIXME
+                # system.configurationRevision = self.rev;
+              }
             ];
+            inherit system;
           };
         };
     };