Comment 1 for bug 1592480

This issue was reported against many other DEs (Cinnamon, MATE, i3wm..).

I would recommend to check XDG_CURRENT_DESKTOP, rather than relying on DBUS interfaces which may or many not be there or may be started after deja-dup itself.

Values for this key are KDE, MATE, X-Cinnamon, Cinnamon. If the goal simply is to show no systray in Shell, just check for the GNOME value and show it everywhere else.

Hope it helps.