New submission from Łukasz Langa: Antoine, #28427 introduces a regression. When used with multiprocessing, the WeakValueDictionary in `multiprocessing.util._afterfork_registry` causes the `remove()` to be invoked during `atexit` and then `sys.meta_path` is None, lots of things is None, including the global `_remove_dead_weakref`.
In effect, I'm getting spew like this: Exception ignored in: <function WeakValueDictionary.__init__.<locals>.remove at 0x7fb2b905e2f0> Traceback (most recent call last): File "/usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/python3.6/weakref.py", line 112, in remove TypeError: 'NoneType' object is not callable Exception ignored in: <function WeakValueDictionary.__init__.<locals>.remove at 0x7fb2b905e2f0> Traceback (most recent call last): File "/usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/python3.6/weakref.py", line 112, in remove TypeError: 'NoneType' object is not callable Exception ignored in: <function WeakValueDictionary.__init__.<locals>.remove at 0x7fb2b905e2f0> Traceback (most recent call last): File "/usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/python3.6/weakref.py", line 112, in remove TypeError: 'NoneType' object is not callable Exception ignored in: <function WeakValueDictionary.__init__.<locals>.remove at 0x7fb2b905e2f0> Traceback (most recent call last): File "/usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/python3.6/weakref.py", line 112, in remove TypeError: 'NoneType' object is not callable When debugged, this 'NoneType' is `_remove_dead_weakref` (weakref.py:117). I'm working on a smaller repro, unfortunately this happens as part of a rather large multiprocessing app so this might take a while. Just wanted to let you know, maybe you'll know right away what the problem is. ---------- assignee: pitrou components: Library (Lib) keywords: 3.5regression, 3.6regression messages: 287475 nosy: lukasz.langa, pitrou priority: normal severity: normal status: open title: weakref spewing exceptions during finalization when combined with multiprocessing type: behavior versions: Python 3.5, Python 3.6, Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue29519> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
