Shoginet leaving behind a lot of zombie processes

[apetresc]

I'm running Shoginet through the Docker container. After a few days, I will invariably end up with some non-trivial number of zombie YanaeuraOu processes:

$ ps aux | grep 'Z'
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root       20469  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21216  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21252  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21256  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21258  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21260  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21262  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21268  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21275  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21293  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
root       21315  0.0  0.0      0     0 ?        Z    Sep10   0:00 [YaneuraOu-by-gc] <defunct>
apetresc  953706  0.0  0.0   6300  2488 pts/2    S+   02:34   0:00 grep Z

This usually indicates a bug in the parent process, not catching the return code of the child processes it fork()ed.

It's not a huge deal, zombie processes don't take up any significant resources and I can always just periodically restart the container. Just kind of annoying, and probably an easy fix.