GNOME Bugzilla – Bug 762445
Always use X11 gdk backend
Last modified: 2016-02-22 13:58:40 UTC
I was recently starting metacity in a wayland session to manage a Xephyr display, and it tried to load the gdk wayland backend, which doesn't make any sense for an X11 window manager. You should call gdk_set_allowed_backends ("x11") - this is exactly what it was invented for.