Find a way to run coverage on python 3.11

[opotowsky]

Typically, github actions are set to run on the latest version of python that we have tested with ARMI. #1341 originally set out to bring all GH actions up to python 3.11, but a known issue with coverage (#1058) prevented us from updating the coverage dependency to a python 3.11 compatible version.

We need to investigate the bug with the coverage version and see if it can be fixed.

I had coverage pinned to 7.2.1 in both setup.py and the coverage workflow, and the action failed.

Update: I'm not sure what the above bug is all about, but coveragepy_lcov has not been updated in 1.5 years and is not python 3.11 compatible. So we will need to completely rework the cooverage step to make it run on python 3.11

[john-science]

Well, that's a bit of a shame.

ARMI currently uses coveragepy_lcov and coveralls.io.

To be honest, I don't love coveralls.io. It's been fine lately, but last year it broke a bunch of times. My guess is if we moved away from that, we would end up using some other tool than coveragepy_lcov anyway.

#1017

[ntouran]

Open issue with coverage_lcov being incompatible with coverage 7.0.0 is here

FWIW, running coverage run -m pytest -x -n 32 armi with python 3.11 works like a charm using coverage 7.2.7, which I guess you already knew.

Looks like pytest can output directly to lcov format though so we can skip the lcov conversion:

commands = pytest --cov --cov-report=lcov

ref: https://github.com/epitools/epitools/pull/72/files

I tried running a modified version of our tox test line:

coverage run --rcfile=.coveragerc -m pytest -n 16 --cov=armi --cov-config=.coveragerc --cov-append --ignore=venv --cov-report=lcov armi

and sure enough coverage.lcov showed up in the working dir! So just a minor change to tox and actions will fix this methinks.