anchor.diff:  
   buildPythonPackage rec {
     pname = "django-silk";
  -  version = "3.0.4";
  +  version = "4.0.1";
   
     # pypi tarball doesn't include test project
     src = fetchFromGitHub {
       owner = "jazzband";
       repo = "django-silk";
       rev = version;
  -    sha256 = "10542yvbchcy8hik2hw3jclb4ic89mxkw0sykag4bw9sv43xv7vx";
  +    sha256 = "0yy9rzxvwlp2xvnw76r9hnqajlp417snam92xpb6ay0hxwslwqyb";
     };
     # "test_time_taken" tests aren't suitable for reproducible execution, but django's
     # test runner doesn't have an easy way to ignore tests - so instead prevent it from picking
  
positive.code: 
    meta = with stdenv.lib; {
      description = "Silky smooth profiling for the Django Framework";
      homepage = "https://github.com/mtford90/silk";
      license = licenses.mit;
      maintainers = with maintainers; [ ris ];
    };
  
negative.code:   postPatch = ''
      substituteInPlace project/tests/test_silky_profiler.py \
        --replace "def test_time_taken" "def _test_time_taken"
      substituteInPlace setup.py \
        --replace 'use_scm_version=True' 'version="${version}"'
    '';
  
    buildInputs = [ mock ];
  