anchor.diff:  buildPythonPackage rec {
     pname = "twentemilieu";
     version = "0.4.2";
  +  format = "pyproject";
     disabled = pythonOlder "3.7";
   
     src = fetchFromGitHub {
  
positive.code: , aiohttp
  , yarl
  , aresponses
  , pytest-asyncio
  , pytestCheckHook
  }:
  
negative.code:     rev = "v${version}";
      sha256 = "1lf31ldbrsmxhbrcg284pwpvjfmwnssv3gqwd5vm2hvd9lwqn6ii";
    };
  
    # coverage tests aren't useful when consuming releases
    postPatch = ''
      substituteInPlace pyproject.toml \
        --replace '--cov' ""
    '';
  
    nativeBuildInputs = [
      poetry-core
    ];
  
    propagatedBuildInputs = [
      aiohttp
  