This is a "bug" (or issue, if you prefer) with a solution, so feel free to set its status to "resolved" immediately. It affects both packages
but, actually, the problem lies elsewhere (dbus?). However, most people will expect the problem to be in those two packages, that's why I am filing it under their names.
Suppose you installed one of the two notification daemons above. Suppose also that you don't run their "standard" window managers - i.e. you run neither GNOME, nor xfce. I run fvwm, you may be running something else. Actually, it should not matter. Suppose further that you have KDE installed, but you don't run it (currently, in your session).
Now, try to send a notification to yourself by typing in a X terminal:
notify-send test test
Nothing happens and syslog shows:
Activating service name='org.freedesktop.Notifications' requested by...
Activated service 'org.freedesktop.Notifications' failed: Process org.freedesktop.Notifications exited with status 1
This happens with any of the two notification daemons above (you can't have both installed at the same time).
The notification daemon does not start. BUT: the file that controls the start of the notification daemon, namely
is correct! There is nothing wrong with it: in each case it contains the right path to the daemon. It is the job of dbus to start it with this information automatically - but it does not.
The real reason here is that there exists another *.Notifications.service file, which (for some reason) takes precedence over the one above:
Dbus seems to try to start the notification daemon with the information from *this* (KDE Plasma) file, rather than the one from your installed notification package. Therefore, it tries to start
and, of course, it fails.
A true solution would be to fix the order of precedence of *.Notifications.service files to conform to the user's situation, but this is not done.
As a workaround, try renaming
Voila! Notifications suddenly work! :-)
I hope this helps somebody with the same problem - I spent half a day chasing it...
@freedesktop-bugs do you have an idea/solution how to proceed here?