anchor.diff:    disabled = pythonOlder "3.6";
   
     src = fetchFromGitHub {
  -    owner = "C4ptainCrunch";
  -    repo = "ics.py";
  +    owner = "ics-py";
  +    repo = "ics-py";
       rev = "v${version}";
       sha256 = "0rrdc9rcxc3ys6rml81b8m8qdlisk78a34bdib0wy65hlkmyyykn";
     };
   
  -  propagatedBuildInputs = [ tatsu arrow ];
  +  propagatedBuildInputs = [
  +    arrow
  +    tatsu
  +  ];
  +
  +  checkInputs = [
  +    pytest-flakes
  +    pytestCheckHook
  +  ];
   
     postPatch = ''
  +    # 0.8 will move to python-dateutil
       substituteInPlace requirements.txt \
         --replace "arrow>=0.11,<0.15" "arrow"
       substituteInPlace setup.cfg --replace "--pep8" ""
     '';
   
  -  checkInputs = [ pytestCheckHook pytest-flakes ];
  +  disabledTests = [
  +    # Failure seems to be related to arrow > 1.0
  +    "test_event"
  +  ];
  +
  +  pythonImportsCheck = [ "ics" ];
   
     meta = with lib; {
       description = "Pythonic and easy iCalendar library (RFC 5545)";
  
positive.code: { lib, buildPythonPackage, fetchFromGitHub, pythonOlder
  , tatsu, arrow
  , pytestCheckHook, pytest-flakes
  }:
  
  buildPythonPackage rec {
  
negative.code:       write ics data in a developer friendly way.
      '';
      homepage = "http://icspy.readthedocs.org/en/stable/";
      changelog = "https://github.com/ics-py/ics-py/releases/tag/v${version}";
      license = licenses.asl20;
      maintainers = with maintainers; [ primeos ];
    };
  }
  