anchor.diff:  { buildPythonPackage
   , lib
   , fetchFromGitLab
  -
  -, isPy3k
  -, isPyPy
  -
   , pyenchant
   , scikit-learn
   , pypillowfight
  
positive.code:   '';
  
    propagatedBuildInputs = [
      pyenchant
      scikit-learn
      pypillowfight
      pycountry
      whoosh
      termcolor
      python-Levenshtein
      libinsane
      pygobject3
      pyocr
      natsort
      pkgs.poppler_gi
      pkgs.gtk3
      distro
      openpaperwork-core
    ];
  
    preCheck = ''
      export HOME=$(mktemp -d)
    '';
  
    nativeBuildInputs = [ pkgs.gettext pkgs.which pkgs.shared-mime-info ];
    preBuild = ''
      make l10n_compile
    '';
  
    checkInputs = [ openpaperwork-gtk psutil pkgs.libreoffice ];
  
    meta = {
      description = "Backend part of Paperwork (Python API, no UI)";
      homepage = "https://openpaper.work/";
      license = lib.licenses.gpl3Plus;
      maintainers = with lib.maintainers; [ aszlig symphorien ];
    };
  }
  
negative.code: 
    sourceRoot = "source/paperwork-backend";
  
    patchPhase = ''
      echo 'version = "${version}"' > src/paperwork_backend/_version.py
      chmod a+w -R ..
  