Bug#1043426: GNOME freezes when Pixel Saver is enabled

[dllud]

Package: gnome-shell-extension-pixelsaver
Version: 1.30-1
Severity: critical

Enabling the Pixel Saver GNOME Shell Extension freezes GNOME
immediately. No mouse or keyboard input is accepted. Only Alt+SysRq+k
gets me out of it.

On subsequent sessions, i.e. with Pixel Saver previously enabled, GNOME
will freeze when any window is opened. I supposed that's when Pixel
Saver's code gets called.

Upon freezing, and getting killed with Alt+SysRq+k, sometimes GNOME
disables all Extensions on the next session (probably a failsafe). As
soon as I enable the Extensions, GNOME freezes immediately, making it
impossible to disable Pixel Saver (greyed out when Extensions are disabled).

Uninstalling gnome-shell-extension-pixelsaver solves it all.

I got a couple segfaults on dmesg, like this:
gnome-shell[11082]: segfault at 78 ip 00007f01cbb92b57 sp
00007f01937fd420 error 4 in libglib-2.0.so.0.7400.6[7f01cbb07000+8d000]
likely on CPU 0 (core 0, socket 0)
I do not get them everytime GNOME freezes, therefore I don't know if
it's related.

On rare occasions, I was able to run sessions with Pixel Saver enabled
(and visually working) without any freeze. The freezing returns upon
restarting the session. I was unable to reproduce the (rare) conditions
which enable Pixel Saver to run smoothly.

I was able to reproduce all this on 2 different desktop machines. Both
x86_64, running Debian 12 bookworm with kernel 6.1.0-10-amd64 and GNOME
Shell 43.6 on Wayland. Apart from that, all hardware (CPU, GPU,
motherboard, display) is different.