Fix documentation build by skipping Sphinx 3.0.0

[pquentin]

Sphinx 3 currently fails with an mysterious ValueError: wrapper loop when unwrapping <MockModule id='139897808864312'>

[codecov]

Codecov Report

Merging #1844 into master will not change coverage by %.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master     #1844   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           22        22           
  Lines         2013      2013           
=========================================
  Hits          2013      2013           

Flag	Coverage Δ
#unittests	98.65% <ø> (-0.95%)	⬇️

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[hodbn]

Apparently this is a known issue (https://bugs.python.org/issue25532#msg253887).

The suggested workaround works on my machine (python3.6), in docs/conf.py:

class MockModule(mock.Mock):
     @classmethod
     def __getattr__(cls, name):
         # See https://bugs.python.org/issue25532#msg253887
         if name == '__wrapped__':
             raise AttributeError()
         return MockModule()

Can you add it?

[sethmlarson]

Give @hodbn's comment a try but if it doesn't work we can pin to 2.x. We don't gain a lot from 3.x from their changelog.

[pquentin]

This is a bug in Sphinx that will be fixed in 3.0.1 so I just skip 3.0.0 for now.

[pquentin]

I fixed the macOS flaky test in #1846, please consider merging this as is: the docs CI passed.

No need for the workaround

[hodbn]

Looks good :)