wayland/plasma doesn't start any more after on my venerable HD5450 since 20210920. It freezes immediately after startup with a black screen and a static mouse pointer. VT switching doesn't work. Recovery via SysRq-e is possible. It's reproducible: Wayland works again after rolling back; re-installation of > 3000 packages results in wayland freezing. Both IceWM and plasma on X11 are working.
I turned out that I shot in my own foot: - I set umask to 0022 globally weeks ago. - 20210920 reinstalled fetchmsttfonts. - Files /usr/share/fonts/truetype/fonts.* were updated without being world-readable. - Xwayland couldn't find the default font any more and blocked during start up. BTW: kwin_wayland was able to run without Xwayland. Sorry for the noise & have fun Bernhard