anchor.diff:    postPatch = ''
       # https://github.com/mwouts/jupytext/pull/885
       substituteInPlace setup.py \
  -      --replace "markdown-it-py[plugins]>=1.0.0b3,<2.0.0" "markdown-it-py[plugins]>=1.0"
  +      --replace "markdown-it-py~=1.0" "markdown-it-py>=1.0.0,<3.0.0"
     '';
   
     preCheck = ''
  
positive.code: 
  buildPythonPackage rec {
    pname = "jupytext";
    version = "1.13.2";
    format = "pyproject";
  
    disabled = pythonOlder "3.6";
  
negative.code:     owner = "mwouts";
      repo = pname;
      rev = "v${version}";
      sha256 = "sha256-HzWAEy7z3qi+lSD3yVBGYclfvKTkG1fTsG29NlKPgQw=";
    };
  
    buildInputs = [
  