No test selected
If you run pytest and it cannot find any tests, for example because you used some
selector and not test matched it, then Pytest will exit with exit code 5.
This is considered a failure by every tool, including Jenkins and other CI systems.
On the other hand you won't see any failed test reported. After all if no tests are run, then none of them fails. This can be confusing.
$ pytest -k long test_by_marker.py
============================= test session starts ============================== platform linux -- Python 3.8.6, pytest-6.1.2, py-1.9.0, pluggy-0.13.1 rootdir: /home/gabor/work/slides/python/examples/pytest, configfile: pytest.ini plugins: flake8-1.0.6, dash-1.17.0 collected 5 items / 5 deselected ============================ 5 deselected in 0.00s =============================
$ echo $? 5