Message 376031 - Python tracker

Aha, interesting bug report. I attached a simplified reproducer.

Output with a Python built in debug mode:
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Objects/frameobject.c:590: _Py_NegativeRefcount: Assertion failed: object has negative ref count
<object at 0x25e8570 is freed>
Fatal Python error: _PyObject_AssertFailed: _PyObject_AssertFailed
Python runtime state: initialized

Current thread 0x00007efd7a2d0740 (most recent call first):
  File "/home/vstinner/bug.py", line 29 in <module>
Abandon (core dumped)
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