anchor.diff:  buildPythonPackage rec {
     pname = "cssselect2";
     version = "0.5.0";
  +  format = "pyproject";
     disabled = pythonOlder "3.5";
   
     src = fetchPypi {
  
positive.code: { lib
  , buildPythonPackage
  , pythonOlder
  , fetchPypi
  , tinycss2
  
negative.code:   postPatch = ''
      sed -i '/^addopts/d' pyproject.toml
    '';
  
    nativeBuildInputs = [
      flit-core
    ];
  
    propagatedBuildInputs = [ tinycss2 ];
  
  