pytest segfault, not with -v

[Marco Sulla]

On Fri, 19 Nov 2021 at 20:38, MRAB <python at mrabarnett.plus.com> wrote:
>
> On 2021-11-19 17:48, Marco Sulla wrote:
> > I have a battery of tests done with pytest. My tests break with a
> > segfault if I run them normally. If I run them using pytest -v, the
> > segfault does not happen.
> >
> > What could cause this quantical phenomenon?
> >
> Are you testing an extension that you're compiling? That kind of problem
> can occur if there's an uninitialised variable or incorrect reference
> counting (Py_INCREF/Py_DECREF).

Ok, I know. But why can't it be reproduced if I do pytest -v? This way
I don't know which test fails.
Furthermore I noticed that if I remove the __pycache__ dir of tests,
pytest does not crash, until I re-ran it with the __pycache__ dir
present.
This way is very hard for me to understand what caused the segfault.
I'm starting to think pytest is not good for testing C extensions.