Mute "Failed to read portal settings" warning
On starting org.gnome.Totem in the gnome-nightly-apps repo on a Fedora 29 system, I get this warning:
(totem:9): Gdk-WARNING **: 20:03:14.004: Failed to read portal settings: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: No such interface “org.freedesktop.portal.Settings” on object at path /org/freedesktop/portal/desktop
Not long after, I get a debug message about the same:
(totem:9): Gdk-DEBUG: 20:03:21.031: Failed to use Settings portal; falling back to gsettings
The GDK code should probably fallback silently when there's no portal available, rather than throw a warning.