Anicorn doesn't understand stale PID file

[vassilevsky]

Hi 👻

I had a small problem with PID file. Maybe you'll want to add anti-measures.

Server was turned off. Unicorn left behind a PID file. It was invalid. But Anicorn kept trying to work with it:

[ 2018/02/10 20:14:03 ] [WARN] Looks like Unicorn is down. Restarting...
[ 2018/02/10 20:14:03 ] Unicorn already works, restarting...
[ 2018/02/10 20:14:03 ] Restarting Unicorn (PID: 3577)...
/usr/bin/anicorn: line 210: kill: (3577) - No such process
[ 2018/02/10 20:14:19 ] [ERROR] Can't restart Unicorn
[ 2018/02/10 20:14:24 ] [WARN] Looks like Unicorn is down. Restarting...
[ 2018/02/10 20:14:24 ] Unicorn already works, restarting...
[ 2018/02/10 20:14:24 ] Restarting Unicorn (PID: 3577)...
/usr/bin/anicorn: line 210: kill: (3577) - No such process
[ 2018/02/10 20:14:40 ] [ERROR] Can't restart Unicorn
[ 2018/02/10 20:14:45 ] [WARN] Looks like Unicorn is down. Restarting...
[ 2018/02/10 20:14:45 ] Unicorn already works, restarting...
[ 2018/02/10 20:14:45 ] Restarting Unicorn (PID: 3577)...
/usr/bin/anicorn: line 210: kill: (3577) - No such process
[ 2018/02/10 20:15:01 ] [ERROR] Can't restart Unicorn

I was able to break this cycle only by manually removing the PID file. After that Anicorn did everything correctly:

[ 2018/02/10 20:15:48 ] [WARN] Looks like Unicorn is down. Restarting...
[ 2018/02/10 20:15:48 ] Starting Unicorn...
[ 2018/02/10 20:16:04 ] Unicorn successfully started (PID: 31271)

Hope this helps!

[andyone]

Fix released as part of 2.1.2 release