[systemd-devel] "systemctl enable" does not report all actions

[Harald Hoyer]

# systemctl disable foo.service bar.service
# systemctl enable foo.service

... reboot ...

# cp /lib/systemd/system/foo.service /etc/systemd/system/foo.service
# vi /etc/systemd/system/foo.service

.. admin forgets, that the old foo.service is already enabled.

# systemctl enable foo.service bar.service
Failed to issue method call: File exists

systemctl gets a dbus error and errors out, because foo.service is already
active via /lib and not /etc, but bar.service was silently enabled and no
messages are printed like the usual:

# systemctl enable bar.service
ln -s '/usr/lib/systemd/system/bar.service'
'/etc/systemd/system/multi-user.target.wants/bar.service'

<rant> "Failed to issue method call: File exists" Even I haven't understood this
error message, without looking in the code!!</rant>