Re: Odd hang in python waiting for child; strace wakes hung process?

[Dan Kegel <dank at kegel dot com>]

On Wed, Mar 21, 2018 at 11:54 AM, Achim Gratz <Stromeko@nexgo.de> wrote:
> Well, with the sporadic hanging/defunct processes at work my routine is
> to send CONT to all Cygwin processes, then HUP/KILL to anything that's
> still not live or gone and then another round of CONT.  This works
> _most_ of the time, anything more stubborn I /bin/kill -f usually.

Since I wrote, both bots hung again.  This time I verified:
0) both had the defunct git process as expected
1) kill -CONT the-pid doesn't do anything, nor does kill -9.  It's truly wedged.
2) the process stays in its spin hang until you ^C strace -p the-pid
3) ^C-ing the strace causes the process to terminate (strace alone doesn't)
4) taskkill /pid the-task /f also kills the process successfully.

So I could write a script that watched for defunct git processes
and taskkilled their parent.  Build jobs would fail, but at least
the bot would stay up.  Of course it would be much nicer if
the cygwin python process didn't get wedged.

Alternately, I suppose I could try running native python...
or cygwin's python3... but dangit, kill -9 should work.
- Dan

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