anchor.diff:        ];
     };
   in releaseTools.nixBuild rec {
  -  name = "hydra-${version}";
  -  version = "2019-03-18";
  +  pname = "hydra";
  +  version = "2019-05-06";
   
     inherit stdenv;
   
     src = fetchFromGitHub {
       owner = "NixOS";
  -    repo = "hydra";
  -    rev = "0721f6623ffb5a4b6a77b499af4eee7d6e4dd6a7";
  -    sha256 = "0b2g2bnbaqpwxx8p81i4gpl4y16i57z5pnjm90fpd0jxnkij3pcg";
  +    repo = pname;
  +    rev = "ff64583d07f046e378a6be596ec0ce7a9e2b7472";
  +    sha256 = "0w88q0saz7si22z3ryim6vdrv9qkwn6l25xfmiapvh5qrnrrdcb9";
     };
   
     buildInputs =
  
positive.code:       perlDeps perl nix
        postgresql # for running the tests
        nlohmann_json
      ] ++ lib.optionals isGreaterNix20 [ boost ];
  
    hydraPath = lib.makeBinPath (
      [ sqlite subversion openssh nix coreutils findutils pixz
  
negative.code: else
  
  let
    perlDeps = buildEnv {
      name = "hydra-perl-deps";
      paths = with perlPackages;
  