anchor.diff:    version = "5.0.0";
     format = "pyproject";
   
  +  disabled = pythonOlder "3.7";
  +
     src = fetchPypi {
       inherit pname version;
  -    sha256 = "sha256-/cFpEvAN/Movd38xaE53Y+D9EYg/SFyHeqtlVUo1D0I=";
  +    hash = "sha256-/cFpEvAN/Movd38xaE53Y+D9EYg/SFyHeqtlVUo1D0I=";
     };
  -
  -  postPatch = ''
  -    substituteInPlace setup.py \
  -      --replace "docutils ~= 0.17.0" "docutils" \
  -      --replace "attrs>=19.1.0,<22" "attrs>=19.1.0"
  -  '';
   
     nativeBuildInputs = [
       setuptools
  
positive.code: { lib
  , buildPythonPackage
  , fetchPypi
  
  # build
  , setuptools
  
  # propagtes
  , sigtools
  , six
  , attrs
  , od
  , docutils
  
  # extras: datetime
  , python-dateutil
  
  # tests
  , pygments
  , unittest2
  , pytestCheckHook
  }:
  
  buildPythonPackage rec {
  
negative.code:     unittest2
    ];
  
    pythonImportsCheck = [
      "clize"
    ];
  
    meta = with lib; {
      description = "Command-line argument parsing for Python";
  