Comment 47 for bug 1642966

> In CUPS everything is OK and as intended.

No -- as above, the maintainer scripts need to stop cups.{socket,path} first before stopping cups.service. Also, as it seems you can entirely drop that .path unit as it's fairly useless -- we don't start cups on demand, but it always starts on boot (in a default install). It would of course be nice to fix that (as I suggested in the upstream bug).

> And there is also another bug in systemd: The *.path file as it comes with CUPS should always start CUPS (if it is not already running) if there is the keepalive file, not only if the keepalive file is newly created.

It does -- that's precisely what happens here: The path unit restarts cups after the maintainer scripts stop it, and that's the core of this bug. So if anything, you want it to be less aggressive, not more :-)

> cups-browsed.service contains "After=cups.service avahi-daemon.service" in its [Unit] section. Is this enough to make cups-browsed being shut down before the shutdown of CUPS is done?

Yes, it is, the Before/After get inversed on stopping units.