[Fedora-packaging] Macronize %pytest

Hello Python packagers, since there is no upstream supported universal test invocation for Python (`python setup.py test` is deprecated and the de-facto-standard `tox` doesn't always do what we want in RPM's %check and/or is not always used by upstreams) and a lot of upstreams use pytest, I'd like to propose a %pytest macros, for standardizing the way pytest is run. Usage: %check %pytest Or with options passed to pyets: %check %pytest -v -m "not network" tests/ (Here ends the tl;dr version.) Why not just use `pytest` or `%{python3} -m pytest` instead of `%pytest`? We want to *test the code we ship*. In the general case this involves: 1. Prepending sys.path with %{buildroot}%{python3_sitelib} (and/or sitearch) 2. Prepending $PATH with %{buildroot}%{_bindir} 3. Ensuring $PWD is not in sys.path So the idea is (untested): %pytest_cmd /usr/bin/pytest %pytest %{expand: PYTHONPATH="${PYTHONPATH:-%{buildroot}%{python3_sitearch}:%{buildroot}%{python3_sitelib}}" \ PATH="%{buildroot}%{_bindir}:$PATH" \ %pytest_cmd } Where PYTHONPATH solves (1), PATH solves (2) and using `/usr/bin/pytest` over `%{python3} -m pytest` kinda solves (3). I say "kinda" because using `python -m pytest` explicitly adds $PWD to sys.path, but using `pytest` doesn't always prevent it. https://docs.pytest.org/en/latest/usage.html#calling-pytest-through-pytho... I've been trying to completely solve (3) in my head in a general way, but it always involves `cd`ing to a temporary directory before running the tests, but plenty of test suites cannot handle that gracefully. Unfortunately Python interpreter doesn't have a flag that says "don't add current directory to sys.path, but respect $PYTHONPATH". In the long term, we might propose to add it. Where to have the macro defined? (Skip this part if not interested.) I was thinking: a) pytest package b) pytest subpackage (required if rpm-build) c) python3-rpm-macros d) python-rpm-macros e) pyproject-rpm-macros And here is the pros and cons: a+) self contained, can change with upstream if needed a+) always present with pytest a-) pytest must co-own macro dir or depend on rpm-build b+) same as a+, but not a- b-) additional layer of complexity c+) easy c+) the macro doesn't need to require pytest, can be used with arbitrary command c+) can be generalized to non-pytest later if desired c-) when pytest CLI changes significantly, we need to change it in different package (but we are not using pytets CLI now at all, just Python/Shell environment variables) c~) technically not always present with pytest, but always present with python3-devel d+-) same as (c) d-) the macro uses python3 specific things e+) the new fancy macros are there e-) the other macros from there (actually pyproject related) are not required for this e-) not always present with pytest nor python3-devel Hence, I'd go with (c) python3-rpm-macros. -- Miro Hrončok -- Phone: +420777974800 IRC: mhroncok