python3 system tests fail to use gRPC

[dhermes]

@tseaver Can you confirm? I'm seeing basic imports failing.

For example:

======================================================================
ERROR: test_log_struct (logging_.TestLogging)
----------------------------------------------------------------------
Traceback (most recent call last):
 File "/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/logging_.py", line 149, in test_log_struct
 entries, _ = _retry_backoff(_has_entries, logger.list_entries)
 File "/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/logging_.py", line 37, in _retry_backoff
 from grpc.beta.interfaces import StatusCode
ImportError: cannot import name 'StatusCode'

[tseaver]

@dhermes Looks like they need to dump the PYTHONPATH=_testing bit.

[dhermes]

But grpcio successfully installs in the Python 3 environment otherwise?

UPDATE: Or you're saying that the GAX version wouldn't be used if the import failed?

[tseaver]

I've run the Py3k system tests with grpcio installed (and the gax-* libraries), but suppressing having _testing on the PYTHONPATH.

[dhermes]

On my machine pip3 install grpcio fails with

could not find grpc_python_plugin (protoc plugin for GRPC Python)

I could put grpc_python_plugin on my path but that won't help Travis.

[tseaver]

I'm beginning to think we should back out all the "just pretend grpc works" stuff we've done (make it a pure extra), disabled by default. I also want to shoot the _testing directory in the head.

[dhermes]

The _testing directory was just there for unit tests (so imports didn't break), never intended to be used in system tests. The real culprit is grpcio.

[tseaver]

I think unit tests don't really need it, either: the bigtable tests could just use `unittest2.skipUnless' like the GAX-related tests in logging and pubsub.

[dhermes]

At the time it was added, there was no Travis environment where grpcio installed, so that was the only way. I'm fine with your suggestion given the current state of things.

[tseaver]

W00t! https://pypi.python.org/pypi/grpcio/1.0.0rc1/#downloads has wheels for Python 3.4 on Linux/Mac/Windows!

[dhermes]

I'm surprised they're at / near a 1.0

[tseaver]

I wonder if pinning the RC would unbreak Travis system-tests3 and Appveyor.