I'm confused by this. Are you sayingget_facecolor doesn't work on master? If so, why are you adding a new method,get_facecolors that returns something different? If this is indeed the right thing to do, then should you also addget_edgecolors?

Might be related:#10797

Are you saying get_facecolor doesn't work on master?

Yes indeed for PolyCollection3D, the code snippet in my top comment that shows what the smoke test does onmaster.

If so, why are you adding a new method, get_facecolors that returns something different

The method from the super classPolyCollection tries to return_facecolors2d which does not necessarily exist. I looked and saw_facecolors did so I used that, but it's possible:

1. it should be_facecolors3d
2. some other function needs to be called to ensure that some magic happens so that_facecolors2d does exist. It looks like_facecolors2d should be set bydo_3d_projection, so perhaps that isn't being called but should be. ThePoly3DCollection code has a comment that it does some magic with these properties, so I'm not really sure which is correct. I should double-check which one makes our code work properly.
3. Something else entirely.

I have not donegit blame but based on how long I've been hitting this issue (months, not years) and browsing the GitHub history, it looks like this probably caused it:

7c40fdf

I'll try to do a propergit blame at some point.

If this is indeed the right thing to do, then should you also add get_edgecolors

Yes this is true, I'll add tests for a few other properties.

Might be related:#10797

#10797 looks related, but I would be surprised if it fixed this bug. But the magical aspects of Poly3DCollection might allow it to fix the bug in some way that is not immediately obvious.

I probably should have tackled this PR sooner -- we now get failures in ourmaster code, so I guess this is in the newly released 2.2.3, too:

https://travis-ci.org/mne-tools/mne-python/jobs/417532117#L2699

Also see#9559. At the end this is the same as#4067. There are some comments by@WeatherGod and an attempted fix in#4090 which never made it through. Not sure what problems there were/are.

I guess this should be closed in favor of#4090, then?

Yes indeed for PolyCollection3D, the code snippet in my top comment that shows what the smoke test does on master.

I'm still confused. Your smoke test callsget_facecolors, whereas the error above is forget_facecolor (nos at the end). If so, I don't see how the PR gets rid of the original error message.

ping@WeatherGod

Ahh I see what you mean. In the older code / base I was working on, the plural was just an alias for the non-plural inPolyCollection. Inmaster I can't find the def ofget_facecolors anywhere, despite it being used in several examples and even incollections.py itself. So it's either just implicitly an alias now, or there are some more bugs / untested lines and examples.

In any case I'll close this for now since I found a suitable workaround, and#4090 is probably the right way to go anyway.