pwgen-secure: recent python versions does not like invalid escape sequences

  postPatch = ''

    shareDir=$out/share/${pname}

    substituteInPlace spwgen.py \

      --replace-fail ' \ ' ' \\ '

    substituteInPlace pwgen_secure/rpg.py \

      --replace "os.path.join(path, 'words.txt')" "os.path.join('$shareDir', 'words.txt')"

      --replace-fail "os.path.join(path, 'words.txt')" "os.path.join('$shareDir', 'words.txt')"

  '';

  propagatedBuildInputs = with python3Packages; [ docopt ];