pytest segfault, not with -v

[Dieter Maurer]

Marco Sulla wrote at 2021-11-20 19:07 +0100:
>I know how to check the refcounts, but I don't know how to check the
>memory usage, since it's not a program, it's a simple library. Is
>there not a way to check inside Python the memory usage? I have to use
>a bash script (I'm on Linux)?

If Python was compiled appropriately (with "PYMALLOG_DEBUG"), `sys` contains
the function `_debugmallocstats` which prints details
about Python's memory allocation and free lists.

I was not able to compile Python 2.7 in this way. But the (system) Python 3.6
of Ubuntu was compiled appropriately.


Note that memory leaks usually do not cause segfaults (unless the application
runs out of memory due to the leak).

Your observation shows (apparently) non-deterministic behavior. In those cases,
minor differences (e.g. with/without "-v") can significantly change
the behavior (e.g. segfault or not). Memory management bugs (releasing memory
still in use) are a primary cause for this kind of behavior in Python
applications.