Pipenv: A instalação de $ pipenv não está funcionando.

❯ pipenv install
Creating a Pipfile for this project...
Creating a virtualenv for this project...
New python executable in /Users/jeyraof/Work/fashion-keyword/.venv/bin/python
Installing setuptools, pip, wheel...done.

Virtualenv location: /Users/jeyraof/Work/fashion-keyword/.venv
No package provided, installing all dependencies.
Pipfile found at /Users/jeyraof/Work/fashion-keyword/Pipfile. Considering this to be the project home.
Installing dependencies from Pipfile...

Traceback (most recent call last):
  File "/usr/local/bin/pipenv", line 11, in <module>
    sys.exit(cli())
  File "/Library/Python/2.7/site-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/Library/Python/2.7/site-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/Library/Python/2.7/site-packages/click/core.py", line 1066, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/Library/Python/2.7/site-packages/click/core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Library/Python/2.7/site-packages/click/core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "/Library/Python/2.7/site-packages/pipenv/cli.py", line 524, in install
    do_init(dev=dev, requirements=requirements, allow_global=system)
  File "/Library/Python/2.7/site-packages/pipenv/cli.py", line 378, in do_init
    click.echo(crayons.yellow('Pipfile.lock not found, creating...', err=True))
TypeError: yellow() got an unexpected keyword argument 'err'

❯

Quando iniciei um novo projeto, enviei o comando $ pipenv install para inicializar a estrutura padrão.
Mas nenhum nome de pacote pypi específico foi aprovado, ele gerou um erro acima.

No entanto, quando passo pypi-package-name na inicialização, funciona bem:
$ pip env install requests .

Como lidar com isso ?

$ pipenv install (blank) um pedido incorreto?