hypothesis --version does not work

[sobolevn]

When I use pip install hypothesis in a clear env and run hypothesis --version, this happens:

» hypothesis --version
Traceback (most recent call last):
  File "/Users/sobolev/Documents/github/returns/.venv/bin/hypothesis", line 6, in <module>
    from hypothesis.extra.cli import main
  File "/Users/sobolev/Documents/github/returns/.venv/lib/python3.7/site-packages/hypothesis/extra/cli.py", line 35, in <module>
    from hypothesis.extra import ghostwriter
  File "/Users/sobolev/Documents/github/returns/.venv/lib/python3.7/site-packages/hypothesis/extra/ghostwriter.py", line 57, in <module>
    import black
ModuleNotFoundError: No module named 'black'

Looks like black is treated as a required dependency right now.

After installing black:

» hypothesis --version
hypothesis, version 5.33.0

[Julian-O]

Looking at setup.py, it looks like if you want to call the command line, you should install the [cli] extra, which installs black and click. See more here

[sobolevn]

@Julian-O yes. But, click is handled differently: https://github.com/HypothesisWorks/hypothesis/blob/master/hypothesis-python/src/hypothesis/extra/cli.py#L41

[Julian-O]

Interesting. Would it be appropriate to catch an import error where you do now import black, with a similar warning?