Fix broken VI test (pytest issue)

[ferrine]

One test is mentioned to be broken in #3775, #3776 is created to remove the test, but it would be a temporary solution.

[rpgoldman]

@ferrine Unfortunately, fixing this for the benefit of test_variational_inference breaks it in the test file that's the source of the fixture.

I think an easier fix might be to give up on figuring out the scoping, and just copy the fixture from the source file into test_variational_inference. This is unsatisfactory, but fighting pytest is unsatisfactory, too.

[ferrine]

I'll do that then

[ferrine]

I think that this may happen due to module scoping

[codecov]

Codecov Report

Merging #3779 into master will increase coverage by 6.59%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #3779      +/-   ##
==========================================
+ Coverage   83.65%   90.25%   +6.59%     
==========================================
  Files         133      133              
  Lines       20336    20670     +334     
==========================================
+ Hits        17013    18656    +1643     
+ Misses       3323     2014    -1309

Impacted Files	Coverage Δ
pymc3/tests/test_shape_handling.py	100% <100%> (+100%)	⬆️
pymc3/tests/test_variational_inference.py	97.77% <100%> (+97.77%)	⬆️
pymc3/sampling.py	77.9% <0%> (-5.22%)	⬇️
pymc3/model.py	89.17% <0%> (+0.12%)	⬆️
pymc3/tests/helpers.py	56.6% <0%> (+1.88%)	⬆️
pymc3/step_methods/hmc/hmc.py	96.66% <0%> (+3.33%)	⬆️
pymc3/distributions/shape_utils.py	100% <0%> (+11.11%)	⬆️
pymc3/memoize.py	96.15% <0%> (+13.46%)	⬆️
pymc3/variational/opvi.py	85.29% <0%> (+17.28%)	⬆️
pymc3/variational/callbacks.py	95.91% <0%> (+18.36%)	⬆️
... and 10 more

[lucianopaz]

Great @ferrine! Looks like you fixed this! For some reason we seem to have to CI builds running in the PR. Maybe we are in the situation described here? I'm in my cellphone and can't take a closer look into that but maybe it would be worth opening an issue

[ferrine]

@ferrine! Looks like you fixed this!

Lol, I did not think I did it and tried to find my PR for 5 mins

[ferrine]

I see some pytest issues on this pytest-dev/pytest#6497