On Mon, 17 Jun 2024 at 18:03, Dale Lobb (Sys Admin) via Cygwin <cygwin@cygwin.com> wrote: > > Greetings, Nicholas; > > > From: Cygwin <cygwin-bounces+dale.lobb=bryanhealth....@cygwin.com> On > > Behalf Of Andrey Repin via Cygwin > > Sent: Monday, June 17, 2024 2:58 AM > > To: Nicholas Williams <nicholas.willi...@zaxiom.com>; cygwin@cygwin.com > > Cc: Andrey Repin <anrdae...@yandex.ru> > > Subject: EXTERNAL SENDER: Re: Cygwin outputting message to stderr on dofork > > EAGAIN failure even when Python exception is caught and handled > > > > Greetings, Nicholas Williams! > We have a Python (installed and run through > > Cygwin) process running on > Windows Server 2022 that was very, very > > occasionally failing when subprocess. check_output was called: > 0 [main] > > python3 28481 > > > > Greetings, Nicholas Williams! > > > > > We have a Python (installed and run through Cygwin) process running on > > > Windows Server 2022 that was very, very occasionally failing when > > > subprocess.check_output was called: > > > > > 0 [main] python3 28481 dofork: child -1 - forked process 16856 died > > > unexpectedly, retry 0, exit code 0xC0000142, errno 11 > > > … > > > subprocess.check_output(["cygpath", "-w", directory.name], > > > encoding="utf-8").strip() > > > File "/usr/lib/python3.9/subprocess.py", line 424, in check_output <> > > > <>return run(*popenargs, stdout=PIPE, timeout=timeout, check=True, <> > > > File "/usr/lib/python3.9/subprocess.py", line 505, in run <> > > > <>with Popen(*popenargs, **kwargs) as process: <> > > > File "/usr/lib/python3.9/subprocess.py", line 951, in __init__ <> > > > <>self._execute_child(args, executable, preexec_fn, close_fds, <> > > > File "/usr/lib/python3.9/subprocess.py", line 1754, in _execute_child > > > self.pid = _posixsubprocess.fork_exec( > > > BlockingIOError: [Errno 11] Resource temporarily unavailable > > > > > Setting aside for a minute the various reasons this might be happening > > > occasionally, which we cannot solve for at this moment, the error number > > > (EAGAIN) indicates that you should “try again.” So that’s exactly what we > > > did. We added a try/catch to the Python code to catch the BlockingIOError > > > and, if and only if the error number is EAGAIN, we try up to two more > > > times. > > > This fixed the problem and caused the application to stop quitting. We > > > output a warning to our log so that we don’t forget about the problem, but > > > the warning only ever appears once, so retrying a single time seems to > > > help. > > > > > However … even though Python handles the dofork error, turns it into a > > > Python exception, and our code catches the Python exception and handles it > > > properly, Cygwin (not Python … Cygwin) still outputs a message to stderr > > > right before our warning message. This Cygwin error message shows up as > > > an error in our log tracking: > > > > > 0 [main] python3 15042 dofork: child -1 - forked process 6780 died > > > unexpectedly, retry 0, exit code 0xC0000142, errno 11 > > > 06/16 13:57:53. 87520: WARNING: Retrying command in 2 seconds due to > > > EAGAIN: [the command we’re running]
Does python require fork(), or can it use posix_spawn() in this case? Dan -- Dan Shelton - Cluster Specialist Win/Lin/Bsd -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
