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SystemError: <method 'is_done' of '_thread._ThreadHandle' objects> returned a result with an exception set #125842
Description
Bug report
Bug description:
There is an unexpected SystemError which is completely outside of user code. I get it with Python 3.13.0 on Windows, but did never see it with Python 3.12.x:
Exception ignored on threading shutdown:
Traceback (most recent call last):
File "C:\Program Files\Python313\Lib\threading.py", line 1524, in _shutdown
if _main_thread._handle.is_done() and _is_main_interpreter():
SystemError: <method 'is_done' of '_thread._ThreadHandle' objects> returned a result with an exception set
Reproduction
The following minimal reproduction script:
import asyncio
import sys
async def run():
p = await asyncio.create_subprocess_exec(*["ssh", "mek@192.168.37.128"])
try:
return await p.wait() # leaving out "return" would help
finally:
if p.returncode is None: # leaving out this "if" statement or the complete "finally" block also would help
p.terminate()
sys.exit(asyncio.run(run()))Run the it and leave the ssh session with sudo reboot now. You get the following output (note the last 5 lines):
mek@mek-ubuntu:~$ sudo reboot now
[sudo] password for mek:
Broadcast message from root@mek-ubuntu on pts/1 (Tue 2024-10-22 15:55:11 CEST):
The system will reboot now!
mek@mek-ubuntu:~$ Connection to 192.168.37.128 closed by remote host.
Connection to 192.168.37.128 closed.
Exception ignored on threading shutdown:
Traceback (most recent call last):
File "C:\Program Files\Python313\Lib\threading.py", line 1524, in _shutdown
if _main_thread._handle.is_done() and _is_main_interpreter():
SystemError: <method 'is_done' of '_thread._ThreadHandle' objects> returned a result with an exception set
There seems to be a strange interaction with async functions, local variables and return values:
- leaving out the "return" keyword at
return await p.wait()prevents the warning message - leaving out the "finally" block or just leave it empty with
passalso omits the warning message - exiting the SSH session with
exitalso omits the warning message
CPython versions tested on:
3.13
Operating systems tested on:
Windows
Activity
colesbury commentedon Oct 22, 2024
cc @mpage.
EDIT : I think it's unlikely that this is a bug in
_ThreadHandle.is_done. I don't see how it could set an exception. I think it's more likely that the problematic exception was set before the invocation of_ThreadHandle.is_done.colesbury commentedon Oct 22, 2024
I can reproduce this on Windows with:
(Without the
import asyncio, the error message is "OverflowError: Python int too large to convert to C long")I think the problem is in
_Py_HandleSystemExit:PyLong_AsLongfor an error returnlongis a 32-bit signed integerGetExitCodeProcessreturns the exit code (via a pointer) as an unsigned 32-bit integer (DWORD).PyLong_AsLongfails due to overflowcpython/Python/pythonrun.c
Lines 603 to 605 in 91ddde4
kunom commentedon Oct 23, 2024
So the issue is that
sys.exit(0xffff_ffff)fails on Windows, even though Windows uses 32-bit unsigned integer exit codes.But since the C standard most probably defines
int(at least Microsoft does), what to do?Would it in this specific case be acceptable to reinterpret-cast the unsigned number, so that
0xffff_ffffrenders as -1? The same thing seems to be done by the Windows command line interpreter (see my first link).pythongh-125842: Fix `sys.exit(0xffff_ffff)` on Windows
colesbury commentedon Oct 23, 2024
Yes, we should interpret
0xffff_ffffinternally as-1instead of failing with an overflow error. We will also need to fix a few places where_Py_HandleSystemExitcan set an exception that isn't expected later on by_Py_Finalize.gh-125842: Fix `sys.exit(0xffff_ffff)` on Windows (#125896)
pythongh-125842: Fix `sys.exit(0xffff_ffff)` on Windows (pythonGH-125896
[3.13] gh-125842: Fix `sys.exit(0xffff_ffff)` on Windows (GH-125896) (G…
colesbury commentedon Oct 24, 2024
This is fixed now in the main and 3.13 branches, and it will be in the 3.13.1 release.
attheratearindam commentedon Dec 27, 2024
Guys Use Python version 3.12 its only issue with the latest version of python (3.13)
pythongh-125842: Fix `sys.exit(0xffff_ffff)` on Windows (python#125896)