I believe the problem is that nothing ensures that the desktop components which select and install software have access to a GUI debconf frontend.
I think the proper solution is for each of the frontends to aptdaemon to depend/recommend a suitable debconf frontend component (libgtk2-perl, libqtgui4-perl/libqtcore4-perl).
For 17.04, this includes at least gnome-software and software-properties-gtk.
I believe the problem is that nothing ensures that the desktop components which select and install software have access to a GUI debconf frontend.
I think the proper solution is for each of the frontends to aptdaemon to depend/recommend a suitable debconf frontend component (libgtk2-perl, libqtgui4- perl/libqtcore4 -perl).
For 17.04, this includes at least gnome-software and software- properties- gtk.