On Thu, 20 Jan 2022 at 23:33, Paul Gevers <elb...@debian.org> wrote: > I looked at the results of the autopkgtest of you package on armhf > because it was showing up as a regression for the upload of > python-defaults and setuptools. I noticed that the test regularly fails, > what's worse, it also seems to hang as the test is killed because it > hits an autopkgtest timeout.
If we look at the backtrace: > Running tests with 160 workers > Exception in thread Thread-1: > Traceback (most recent call last): > File "/usr/lib/python3.9/threading.py", line 973, in _bootstrap_inner > self.run() > File "/usr/lib/python3.9/concurrent/futures/process.py", line 317, in run > result_item, is_broken, cause = self.wait_result_broken_or_wakeup() > File "/usr/lib/python3.9/concurrent/futures/process.py", line 376, in > wait_result_broken_or_wakeup > worker_sentinels = [p.sentinel for p in self.processes.values()] > File "/usr/lib/python3.9/concurrent/futures/process.py", line 376, in > <listcomp> > worker_sentinels = [p.sentinel for p in self.processes.values()] > RuntimeError: dictionary changed size during iteration This is all Python's internal code. Further, Meson does not do any fancy threading stuff itself, it uses Python's thread and process executors to queue up a bunch of work and then wait for it to be done. According to Python's documentation you don't need to do any locking or similar to submit new work, you can call the submit method directly. All of this would seem to indicate that the issue might lie somewhere in Python's multithreading code. At the very least I have no idea how I should go about debugging that issue.
