New submission from Jack O'Connor:
The following test script prints a KeyboardInterrupt traceback (expected), but
also an AttributeError traceback (unexpected):
import asyncio
@asyncio.coroutine
def main():
raise KeyboardInterrupt
asyncio.get_event_loop().run_until_complete(main())
Traceback (most recent call last):
File "test.py", line 9, in <module>
asyncio.get_event_loop().run_until_complete(main())
File "/usr/lib/python3.4/asyncio/base_events.py", line 203, in
run_until_complete
self.run_forever()
File "/usr/lib/python3.4/asyncio/base_events.py", line 184, in run_forever
self._run_once()
File "/usr/lib/python3.4/asyncio/base_events.py", line 817, in _run_once
handle._run()
File "/usr/lib/python3.4/asyncio/events.py", line 39, in _run
self._callback(*self._args)
File "/usr/lib/python3.4/asyncio/tasks.py", line 321, in _step
result = next(coro)
File "/usr/lib/python3.4/asyncio/tasks.py", line 103, in coro
res = func(*args, **kw)
File "test.py", line 6, in main
raise KeyboardInterrupt
KeyboardInterrupt
--- Logging error ---
Traceback (most recent call last):
--- Logging error ---
Traceback (most recent call last):
Exception ignored in: <bound method Task.__del__ of
Task(<coro>)<exception=KeyboardInterrupt()>>
Traceback (most recent call last):
File "/usr/lib/python3.4/asyncio/futures.py", line 184, in __del__
File "/usr/lib/python3.4/asyncio/base_events.py", line 725, in
call_exception_handler
File "/usr/lib/python3.4/logging/__init__.py", line 1296, in error
File "/usr/lib/python3.4/logging/__init__.py", line 1402, in _log
File "/usr/lib/python3.4/logging/__init__.py", line 1412, in handle
File "/usr/lib/python3.4/logging/__init__.py", line 1482, in callHandlers
File "/usr/lib/python3.4/logging/__init__.py", line 846, in handle
File "/usr/lib/python3.4/logging/__init__.py", line 977, in emit
File "/usr/lib/python3.4/logging/__init__.py", line 899, in handleError
File "/usr/lib/python3.4/traceback.py", line 169, in print_exception
File "/usr/lib/python3.4/traceback.py", line 153, in _format_exception_iter
File "/usr/lib/python3.4/traceback.py", line 18, in _format_list_iter
File "/usr/lib/python3.4/traceback.py", line 65, in _extract_tb_or_stack_iter
File "/usr/lib/python3.4/linecache.py", line 15, in getline
File "/usr/lib/python3.4/linecache.py", line 41, in getlines
File "/usr/lib/python3.4/linecache.py", line 126, in updatecache
File "/usr/lib/python3.4/tokenize.py", line 437, in open
AttributeError: 'module' object has no attribute 'open'
The issue is that Task._step() calls self.set_exception() for both Exceptions
and BaseExceptions, but it reraises BaseExceptions. That means that the
BaseEventLoop never gets to call future.result() to clear the exception when
it's a BaseException. Future.__del__ eventually tries to log this uncleared
exception, but something about the circumstances of program exit (caused by the
same exception) has already cleaned up the builtins needed for logging.
Is that __del__ violating some best practices for finalizers by calling such a
complicated function? Either way, I'm not sure this case should be considered
an "unretrieved exception" at all. It's propagating outside the event loop
after all. Should Task._step() be setting it in the first place, if it's going
to reraise it? Should it be set without _log_traceback=True somehow?
----------
components: asyncio
messages: 226985
nosy: gvanrossum, haypo, oconnor663, yselivanov
priority: normal
severity: normal
status: open
title: KeyboardInterrupt inside a coroutine causes AttributeError
type: behavior
versions: Python 3.4
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue22428>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
