anchor.diff:      whoosh
     ];
   
  -  disabled = !isPy3k;
  +  postPatch = ''
  +    substituteInPlace setup.py \
  +      --replace "lxml<=4.3.5" "lxml~=4.3" \
  +      --replace "python-slugify>=1.2.6,<4" "python-slugify"
  +  '';
   
  -  doCheck = !stdenv.isDarwin;
  +  # pytest seems to hang with python3.8
  +  doCheck = !stdenv.isDarwin && pythonOlder "3.8";
   
     checkInputs = ([
       pytest
  
positive.code: , pyyaml, chardet, beautifulsoup4, colorama, bibtexparser
  , pylibgen, click, python-slugify, habanero, isbnlib
  , prompt_toolkit, pygments, stevedore, tqdm, lxml
  , python-doi, isPy3k
  #, optional, dependencies
  , whoosh, pytest
  , stdenv
  
negative.code: buildPythonPackage rec {
    pname = "papis";
    version = "0.9";
    disabled = !isPy3k;
  
    # Missing tests on Pypi
    src = fetchFromGitHub {
  