anchor.diff:  
   buildPythonPackage rec {
     pname = "papis";
  -  version = "0.9";
  +  version = "0.10";
     disabled = !isPy3k;
   
     # Missing tests on Pypi
  
positive.code:   postPatch = ''
      substituteInPlace setup.py \
        --replace "lxml<=4.3.5" "lxml~=4.3" \
        --replace "python-slugify>=1.2.6,<4" "python-slugify"
    '';
  
  
negative.code:     owner = "papis";
      repo = pname;
      rev = "v${version}";
      sha256 = "0fmrvxs6ixfwjlp96b69db7fpvyqfy2n3c23kdz8yr0vhnp82l93";
    };
  
    propagatedBuildInputs = [
      requests filetype pyparsing configparser arxiv2bib
      pyyaml chardet beautifulsoup4 colorama bibtexparser
      click python-slugify habanero isbnlib
      prompt_toolkit pygments typing-extensions
      stevedore tqdm lxml
      python-doi
      # optional dependencies
  