Install a fake local grpc-google-iam-v1 to resolve the version conflict.

[dhermes]

See https://readthedocs.org/projects/google-cloud-python/builds/4449660/ for validation of this fact (at 388b9bf). This is a temporary hack to workaround the fact that the latest (0.10.1) gapic-google-pubsub-v1 relies on grpc-google-iam-v1 0.10.0, but they have contradicting bounds on oauth2client:

• 'oauth2client>=1.4.11, <2.0.0', in grpc-google-iam-v1
• 'oauth2client>=3.0.0, <4.0.0dev', in gapic-google-pubsub-v1

Fixes #2405.

WORTH NOTING: I am sending the PR from a branch I created on GoogleCloudPlatform. I created it here so I could test if the hack worked on RTD without having to keep behaving badly with premature merges.

/cc @bjwatson

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ASIDE: @tseaver @jonparrott Any idea why pip is cool with the version conflict but setuptools isn't? (Evidence: python setup.py install fails at the "Processing dependencies" step with the conflict described above, but pip is happy to let it happen.)

[theacodes]

@dhermes not sure - what does pip say is the collected and installed packages when you do it?

[theacodes]

@bjwatson it's pretty easy to support a wide range of oauth2client versions, any reason to keep the bounds so tight?

[dhermes]

Only failure was pylint on my fake directory: https://travis-ci.org/GoogleCloudPlatform/google-cloud-python/builds/163282822#L1000

Just added grpc-google-iam-v1-fake to IGNORED_DIRECTORIES and pushed over the original commit.

@tseaver Any issues with merging this while we wait for the version conflict to be resolved?

[tseaver]

https://pypi.python.org/pypi/grpc-google-iam-v1/0.9.0 and https://pypi.python.org/pypi/grpc-google-iam-v1/0.10.1 are released.

[bjwatson]

@jonparrott Paranoia, per semver. I can relax it. What do you suggest? >=1.4.11, <4.0.0?

[dhermes]

Best closed PR ever!

I just manually rebuilt latest (at 5a0e492) at it succeeded: https://readthedocs.org/projects/google-cloud-python/builds/4453698/