anchor.diff:  { lib, fetchFromGitHub, fetchpatch
  -, python3, xdg_utils
  +, python36, xdg_utils
   }:
   
  -python3.pkgs.buildPythonApplication rec {
  +python36.pkgs.buildPythonApplication rec {
     pname = "papis";
     version = "0.7.5";
   
  
positive.code:     install -Dt "$out/etc/bash_completion.d" scripts/shell_completion/build/bash/papis
    '';
  
    checkInputs = (with python3.pkgs; [
      pytest
    ]) ++ [
      xdg_utils
  
negative.code:     sha256 = "0cmagfdaaml1pxhnxggifpb47z5g1p231qywnvnqpd3dm93382w1";
    };
  
    propagatedBuildInputs = with python36.pkgs; [
      click requests filetype pyparsing configparser
      arxiv2bib pyyaml chardet beautifulsoup4 prompt_toolkit
      bibtexparser python-slugify pyparser pylibgen
  