anchor.diff:  buildPythonPackage rec {
     pname = "clize";
     version = "4.2.1";
  +  format = "pyproject";
   
     src = fetchPypi {
       inherit pname version;
  
positive.code: { lib
  , buildPythonPackage
  , fetchPypi
  
  # propagtes
  , sigtools
  
negative.code: 
    postPatch = ''
      substituteInPlace setup.py \
        --replace "docutils ~= 0.17.0" "docutils" \
        --replace "attrs>=19.1.0,<22" "attrs>=19.1.0"
    '';
  
    nativeBuildInputs = [
      setuptools
    ];
  
    propagatedBuildInputs = [
      attrs
  