?? ()
?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
handle_property_change(_GdkScreen*, char const*) ()