To change to the old behavior, pass --quiet. The aim is to be make it easier to debug issues only reproducing in the CI. https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1289
https://gitlab.gnome.org/GNOME/mutter/merge_requests/866
Clutter doesn't hold anymore backend implementations, move tests where we have one that we may assign. https://gitlab.gnome.org/GNOME/mutter/merge_requests/672