In order to replace the default Xubuntu deamon notifications with dunst, you have to, once dunst compiled and installed, disable the dbus service file :
sudo mv /usr/share/dbus-1/services/org.xfce.xfce4-notifyd.Notifications.service /usr/share/dbus-1/services/org.xfce.xfce4-notifyd.Notifications.service.disabled
You must then check that the /usr/share/dbus-1/services/dunst.service file exists, or create it if necessary
sudo vim /usr/share/dbus-1/services/dunst.service
The content of the file will be as follows:
[D-BUS Service] Name=org.freedesktop.Notifications Exec=/usr/bin/dunst
It works because Dunst is started automatically via a dbus service usually located in:
However, this does not seem to be the best of techniques, because from a ‘Linuxian’ point of view, manually change files in ‘/ usr’ are never well regarded. I would update this article if I find a more elegant solution.