units: drop OnFailure= from .target units

[keszybz]

See c80a9a3, target units can't fail.
I guess we need to figure out some replacement functionality, but at least
let's avoid the warning from systemd for now.

[keszybz]

bionic-i386 seems to fail with a timeout, probably unrelated.
travis fails in Debian Testing (clang) build, unrelated too.

[intelfx]

@keszybz is it right? .target units can fail, for example by dependencies, no?

I've just had an occurrence when one of my machines booted up to multi-user.target despite having failed a non-optional mount in fstab. I suppose this is why?

# systemctl status mnt-data.mount local-fs.target multi-user.target
● mnt-data.mount - /mnt/data
     Loaded: loaded (/etc/fstab; generated)
     Active: inactive (dead)
      Where: /mnt/data
       What: /dev/disk/by-label/storage
       Docs: man:fstab(5)
             man:systemd-fstab-generator(8)

Jul 08 15:19:11 anystation systemd[1]: Dependency failed for /mnt/data.
Jul 08 15:19:11 anystation systemd[1]: mnt-data.mount: Job mnt-data.mount/start failed with result 'dependency'.

● local-fs.target - Local File Systems
     Loaded: loaded (/usr/lib/systemd/system/local-fs.target; static; vendor preset: disabled)
     Active: inactive (dead) since Wed 2020-07-08 15:17:40 MSK; 55min ago
       Docs: man:systemd.special(7)

Jul 08 15:17:40 archlinux systemd[1]: Stopped target Local File Systems.
Jul 08 15:19:11 anystation systemd[1]: Dependency failed for Local File Systems.
Jul 08 15:19:11 anystation systemd[1]: local-fs.target: Job local-fs.target/start failed with result 'dependency'.
Warning: journal has been rotated since unit was started, output may be incomplete.

● multi-user.target - Multi-User System
     Loaded: loaded (/usr/lib/systemd/system/multi-user.target; static; vendor preset: disabled)
     Active: active since Wed 2020-07-08 15:19:12 MSK; 53min ago
       Docs: man:systemd.special(7)

Jul 08 15:19:12 anystation systemd[1]: Reached target Multi-User System.

[keszybz]

According to c80a9a3, they can't. @poettering?

[intelfx]

@keszybz if targets can't fail, then how did it ever work before? Meaning the emergency transition on a failed mount.

[boucman]

all units can fail on timeouts... right ? there are timeouts in the [Unit] section IIRC

[intelfx]

No, that's job timeouts. When a job times out, the target unit doesn't change state: JobTimeoutSec=.

[arvidjaar]

According to c80a9a3, they can't.

You are aware that OnFailure is also triggered by job failures, are not you?

        /* Trigger OnFailure dependencies that are not generated by
         * the unit itself. 

systemd/src/core/job.c

Line 1053 in 24e2494

/* Trigger OnFailure dependencies that are not generated by