1 files changed, 13 insertions, 7 deletions
diff --git a/krebs/krops.nix b/krebs/krops.nix
index ab7524941..94418fdc2 100644
--- a/krebs/krops.nix
+++ b/krebs/krops.nix
@@ -9,15 +9,21 @@
 
   krebs-source = { test ? false }: rec {
     nixpkgs = if test then {
-      file = {
-        path = toString (pkgs.fetchFromGitHub {
+      derivation = let
+        rev = (lib.importJSON ./nixpkgs.json).rev;
+        sha256 = (lib.importJSON ./nixpkgs.json).sha256;
+      in ''
+        with import (builtins.fetchTarball {
+          url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
+          sha256 = "${sha256}";
+        }) {};
+        pkgs.fetchFromGitHub {
           owner = "nixos";
           repo = "nixpkgs";
-          rev = (lib.importJSON ./nixpkgs.json).rev;
-          sha256 = (lib.importJSON ./nixpkgs.json).sha256;
-        });
-        useChecksum = true;
-      };
+          rev = "${rev}";
+          sha256 = "${sha256}";
+        }
+      '';
     } else {
       git = {
         ref = (lib.importJSON ./nixpkgs.json).rev;