Pytest treating warning as exception

I’m running pytest with:
python -m pytest tests/ -vv -rsx

However, it is treating warnings as errors:

_______________ ERROR collecting tests/ ________________
tests/ in <module>
    import synthesis_report in <module>
    from lib import cmdLineArgs, varsModule
lib/ in <module>
    import imp
venv/lib/python3.7/ in <module>
    DeprecationWarning, stacklevel=2)
E   DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses

How do I make it not do this?

This might be a better question for the pytest community itself: