Control: severity -1 important
Control: tags -1 + trixie moreinfo
Control: forwarded -1 https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/8983
On Mon, 19 Jan 2026 at 11:28:42 +0100, Alberto Garcia wrote:
after the Debian 13.2 -> 13.3 upgrade I noticed that when I boot my
computer and log in with GDM the screen goes immediately blank, "No
HDMI signal" and the monitor goes to standby mode.
What GPU(s) and monitor layout/configuration is this? Can you share your
~/.config/monitors.xml? (with serial numbers, etc. redacted if you want)
From other, similar issue reports, it seems there might be a correlation
with AMD GPUs (but my work laptop is running the updated gnome-shell on
an AMD GPU without apparent problems, so probably there is some other
factor involved).
It's interesting that this happens for your own login session, but not
for gdm, both of which are really gnome-shell. That would imply that gdm
is choosing a configuration that does work, but your own login session
has a configuration that (for whatever reason) doesn't work.
After reverting a few packages I noticed that downgrading gnome-shell
from 48.7-0+deb13u1 to 48.4-1~deb13u1 solves the problem.
Please confirm: if I understand you correctly, you can reproduce or work
around this by upgrading/downgrading only the src:gnome-shell family of
packages, without altering other packages like the kernel, src:mutter or
Mesa? If true, this is very helpful - it means we probably don't have to
look for regressions outside src:gnome-shell.
We might have to ask you to try 48.5 and 48.6 packages to try to narrow
this down further.
It would probably be helpful if you could comment on the forwarded
upstream bug report, rather than having the Debian GNOME team interposed
in the middle.
Thanks,
smcv
