[New-bugs-announce] [issue23353] gnerator bug with exception: tstate->exc_value is not cleared after an except block

[STINNER Victor]

New submission from STINNER Victor:

Since my changeset a5efd5021ca1, the Python test suite starts to fail randomly. Running test_asyncio modifies sys.exc_info(): it is not (None, None, None) after the execution of test_asyncio. The problem comes from test_cancel_make_subprocess_transport_exec() of Lib/test/test_asyncio/test_subprocess.py.

I tried to write a simple script which does not depend on Python to reproduce the issue. See attached excinfo_bug2.py script.

Output:
---
exc_info after except (<class '__main__.MyException'>, MyException(), <traceback object at 0x7f09201ad7c8>)
exc_info at exit (<class '__main__.MyException'>, MyException(), <traceback object at 0x7f09201abd08>)
---

exc_info is supposed to be (None, None, None), at least at exit.

I will try to write an even simpler script to identify the bug.

----------
files: excinfo_bug2.py
messages: 235033
nosy: haypo
priority: normal
severity: normal
status: open
title: gnerator bug with exception: tstate->exc_value is not cleared after an except block
versions: Python 3.4, Python 3.5
Added file: http://bugs.python.org/file37922/excinfo_bug2.py

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue23353>
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