Sickrage pid file kept vanishing after reboots. Turns out /var/run is tmpfs. Use tmpfiles.d!
https://www.freedesktop.org/software/systemd/man/tmpfiles.d.html
/etc/tmpfiles.d/sickrage.conf:
D /var/run/sickrage 0755 sickrage sickrage
Found through https://blog.hqcodeshop.fi/archives/93-Handling-varrun-with-systemd.html