Enable PyQt 5.15 tests on macOS + Windows

[dhomeier]

Description

Experiment to investigate the failing tests from #2269; on Linux may be X11 related.
The collection error

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl, xcb.

appears to be Linux only.

[codecov]

Codecov Report

Merging #2272 (16708c9) into main (3d09f59) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2272   +/-   ##
=======================================
  Coverage   88.07%   88.07%           
=======================================
  Files         247      247           
  Lines       23279    23279           
=======================================
  Hits        20502    20502           
  Misses       2777     2777           

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[dhomeier]

macos: py39-test-pyqt515 passing, windows: py39-test-pyqt515 running past collection; probing a couple more combinations now.

[dhomeier]

@astrofrog this looks like an incomplete installation on the Linux side – see https://forum.qt.io/post/666128 .
Is the PyQt5 package itself broken or can/should we try to ensure installation of the library ourselves
(something like apt-get install libxcb-xinerama0-dev; however one tells azure or tox about that)?

[astrofrog]

You can install additional libraries on Linux in azure in the following section in the azure pipelines config:

libraries:
      apt:
        - libxkbcommon-x11-0

I think it's expected that we have to install additional libraries on Linux, although annoying.

[dhomeier]

I think it's expected that we have to install additional libraries on Linux, although annoying.

Yes, I tried to run python -m tox -e py38-test-pyqt515 manually on a RH system with anaconda, and it installed its PyQt5.15 package without any matching libQt5Core.so. pytest did not even get as far as finding glue-core...

[dhomeier]

OK, must have been another -dev package or the libxcb* ones.
I am letting the whole set of combinations run once, then to decide which should stay in the standard configuration.

[astrofrog]

Looks good! Feel free to merge if this is ready to go

[dhomeier]

Which pyqt515 versions should I keep? All 4x3 combinations seems a bit excessive... ;-)

Maybe

    - linux: py39-test-pyqt515

    # Test against latest developer versions of some packages
    - linux: py310-test-pyqt515-dev-all

    - macos: py310-test-pyqt515-all
    # The following failed due to https://github.com/jupyter/qtconsole/issues/400 - fixed upstream
    - windows: py38-test-pyqt514-all
    - windows: py310-test-pyqt515

(replacing linux: py310-test-pyqt514-dev-all with linux: py310-test-pyqt515-dev-all)?

[astrofrog]

Yes that seems reasonable - thanks!