Systemd is comprehensive and the best of it is: it is working. SystemV and upstart couldn’t provide nearly the comfort and reliability systemd is now providing.
System apt upgrade went through. Well. Almost. apt upgrade installed the packages fine and at the end tried to restart mysqld. But not too hard.
Issue:
Okt 03 14:29:50 systemd[22776]: mysql.service: Failed to determine user credentials: No such process Okt 03 14:29:50 systemd[22776]: mysql.service: Failed at step USER spawning /usr/share/mysql/mysql-systemd-start: No such process
Solution: C’mon, just reexec it, FWIW!
~# systemctl daemon-reexec
The package’s post-install script should’ve called a systemctl daemon-reexec.
Rant: This issue shouldn’t even have crept up. In the post-install script just DTRT.