Bug report

Bug description:

Short untested example:

lst = ... # a numpy darray
res = func(lst.tolist()) # function in the C extension. edits in-place lst.tolist() -> returns a List. res depends on `lst`
print(res[0]) # Segmentation fault when accessing res in some way

func edits lst.tolist() in-place, and res depends on lst.tolist(), possibly res is lst.tolist().
We get a segfault when printing. It results of a GC collection error, probably because lst.tolist() is invalidly being freed. Assigning lst.tolist() to a variable fixes the segfault.

It might be Python intent to act like this.

CPython versions tested on:

3.9

Operating systems tested on:

Linux