anchor.diff:      sha256 = "fa2662097c66f920f53f70621c6c58ca4a3c4d3434205e608e121b5b3b71f4f3";
     };
   
  +  propagatedBuildInputs = [ setuptools ];
  +
     checkInputs = [ pytest mock pytestcov coverage ];
   
     prePatch = ''
  
positive.code: { stdenv, buildPythonPackage, fetchPypi
  , pytest, mock, pytestcov, coverage }:
  
  buildPythonPackage rec {
    pname = "gunicorn";
  
negative.code:       --replace "coverage>=4.0,<4.4" "coverage"
    '';
  
    # better than no tests
    checkPhase = ''
      $out/bin/gunicorn --help > /dev/null
    '';
  
    pythonImportsCheck = [ "gunicorn" ];
  
    meta = with stdenv.lib; {
      homepage = https://pypi.python.org/pypi/gunicorn;
  