[issue46070] [subinterpreters] crash when importing _sre in subinterpreters in parallel (Python 3.9 regression)

[Alban Browaeys]

Alban Browaeys <prahal at yahoo.com> added the comment:

While bisecting main branch I did not only get segfaults but also exceptions, namely:

$ ./python  ../python-crash-kodi/sqlite3_crash.py 
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 81, in register_adapters_and_converters
    register_adapter(datetime.datetime, adapt_datetime)
KeyError: 'isoformat'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 83, in register_adapters_and_converters
    register_converter("timestamp", convert_timestamp)
KeyError: 'timepart_full'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 83, in register_adapters_and_converters
    register_converter("timestamp", convert_timestamp)
KeyError: 'day'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 83, in register_adapters_and_converters
    register_converter("timestamp", convert_timestamp)
KeyError: 'month'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 83, in register_adapters_and_converters
    register_converter("timestamp", convert_timestamp)
KeyError: 'year'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 83, in register_adapters_and_converters
    register_converter("timestamp", convert_timestamp)
KeyError: 'timepart'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "/home/prahal/Projects/WIP/libreelec/cpython_bisect/Lib/sqlite3/dbapi2.py", line 83, in register_adapters_and_converters
    register_converter("timestamp", convert_timestamp)
KeyError: 'datepart'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
KeyError: 'convert_timestamp'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
KeyError: 'convert_date'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
KeyError: 'adapt_datetime'
Exception ignored deletion of interned string failed:
Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
KeyError: 'adapt_date'


The 3.10 branch bisect pointed to one commit that fix the crash after 3.10.1 which is 72c260cf0c71eb01eb13100b751e9d5007d00b70 [3.10] bpo-46006: Revert "bpo-40521: Per-interpreter interned strings (GH-20085)" (GH-30422) (GH-30425) which makes sense regarding main branch logs. It is commit 
35d6540c904ef07b8602ff014e520603f84b5886 in the main branch.

What remains to be seen is why "bpo-46070: _PyGC_Fini() untracks objects (GH-30577)" looks fine in the main branch (though it has no effect on the import crash) and not in 3.9 and 3.10 branch.
Mind in the main branch "bpo-46006: Revert "bpo-40521: Per-interpreter interned strings (GH-20085)" (GH-30422)" was already applied when "bpo-46070: _PyGC_Fini() untracks objects (GH-30577)" went in so it was also unrelated to the fix of the initial report.

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue46070>
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