anchor.diff:      pyparsing
       wcwidth
     ]
  -  ++ stdenv.lib.optional (pythonOlder "3.5") contextlib2
  +  ++ stdenv.lib.optionals (pythonOlder "3.5") [contextlib2 typing]
     ;
  +
  +
  +  doCheck = !stdenv.isDarwin;
  +  # pytest-cov
  +  # argcomplete  will generate errors
  +  checkInputs= [ pytest mock which vim glibcLocales pytest-mock ]
  +        ++ stdenv.lib.optional (pythonOlder "3.6") [ mock ];
  +  checkPhase = ''
  +    # test_path_completion_user_expansion might be fixed in the next release
  +    py.test -k 'not test_path_completion_user_expansion'
  +  '';
   
     meta = with stdenv.lib; {
       description = "Enhancements for standard library's cmd module";
  
positive.code:     export PATH=$(realpath bin):$PATH
    '';
  
    checkInputs= [ pytest mock which vim glibcLocales ];
    checkPhase = ''
      # test_path_completion_user_expansion might be fixed in the next release
      py.test -k 'not test_path_completion_user_expansion'
    '';
    doCheck = !stdenv.isDarwin;
    disabled = !isPy3k;
  
    buildInputs = [
  
negative.code: { stdenv, fetchPypi, buildPythonPackage, pythonOlder, isPy3k
  , pyperclip, six, pyparsing, vim, wcwidth, colorama
  , contextlib2 ? null, typing ? null, setuptools_scm
  , pytest, mock ? null, pytest-mock
  , which, glibcLocales
  }:
  buildPythonPackage rec {
    pname = "cmd2";
    version = "0.9.6";
  
    src = fetchPypi {
      inherit pname version;
      sha256 = "0279p76n6yny6psys9fc6yjdrqiisbpmrl59a2vxy56hi7094kaw";
    };
  
    LC_ALL="en_US.UTF-8";
  