anchor.diff:  
   buildPythonPackage rec {
     pname = "pytest-cases";
  -  version = "3.6.4";
  +  version = "3.6.5";
  +  format = "setuptools";
  +
     disabled = pythonOlder "3.6";
   
     src = fetchPypi {
       inherit pname version;
  -    sha256 = "sha256-m2oxE7q46TWadhZgpwTAHKep5ZN9LG1VNCRJkPz5W1E=";
  +    sha256 = "sha256-JZfQI6dgYFHWUbCMuHD78eBi9svoV5zkX887V9xFLNw=";
     };
   
     nativeBuildInputs = [
  
positive.code:   ];
  
    postPatch = ''
      substituteInPlace setup.cfg --replace "pytest-runner" ""
    '';
  
    # Tests have dependencies (pytest-harvest, pytest-steps) which
  
negative.code:   # makefun, pytest-*) have circular dependecies.
    doCheck = false;
  
    pythonImportsCheck = [
      "pytest_cases"
    ];
  
    meta = with lib; {
      description = "Separate test code from test cases in pytest";
  