** Description changed:
[ Impact ]
The fix for bug 2120413 was supposed to retry the preferred display
server option (generally Wayland) up to 5 times before falling back to
another option (generally Xorg).
After the update however, gdm is seen retrying Wayland forever instead and
never falling back to Xorg.
This only happens when auto-login is enabled. With auto-login disabled
instead, GDM correctly falls back to Xorg after 5 retries of Wayland.
Evidence:
* no auto-login:
https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/2129777/+attachment/5920253/+files/journal-
last-gdm3-version-no-autologin.txt
* auto-login:
https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/2129777/+attachment/5920254/+files/journal-
last-gdm3-version-autologin.txt
[ Test Plan ]
1. Log-in
2. Break GNOME Wayland:
mkdir -p ~/.config/systemd/user/[email protected]/
- printf '[Service]\nExecStart=/usr/bin/true\n' >
~/.config/systemd/user/[email protected]/override.conf
+ printf '[Service]\nExecStart=\nExecStart=/usr/bin/true\n' >
~/.config/systemd/user/[email protected]/override.conf
3. Enable GDM auto-login in /etc/gdm3/custom.conf
3. Reboot
4. Verify that you got logged-in to your GNOME desktop
5. Verify that `echo $XDG_SESSION_TYPE` is x11
6. Log-out
8. Verify that the log-in screen is visible
Restore GNOME Wayland with
rm -rf ~/.config/systemd/user/[email protected]/
[ Where problems could occur ]
The patch modifies what happens after a user session terminates.
One effect is to correctly handle termination after a failed session, but a
side-effect might impact handling termination after a successful session.
For that reason the test plan verifies that logging-out still works as
expected.
[ Other info ]
The bug is Invalid for questing and newer because there is no Xorg
session to fall back to, as there's only Wayland.
[ Original bug report ]
Hello,
This issue is probably linked to bug #2128840, but in my case,
MUTTER_DEBUG_FORCE_EGL_STREAM env var is not set.
In short, upgrading to gdm3 46.2-1ubuntu1~24.04.3 and rebooting, caused
the desktop could not be reached: black screen only. Removing the
Automatic Login entries from /etc/gdm3/custom.conf and rebooting fixed
the issue. Downgrading to the previous version (46.2-1ubuntu1~24.04.1)
also fixed the issue.
System info will be shared in the next comment(s).
Note: the issue is visible on a laptop I don't own, and I don't easily
have access. I tried to provide as much data as I could, but "quick
tests" might be difficult.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: gdm3 46.2-1ubuntu1~24.04.3
ProcVersionSignature: Ubuntu 6.8.0-86.87-generic 6.8.12
Uname: Linux 6.8.0-86-generic x86_64
ApportVersion: 2.28.1-0ubuntu3.8
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Fri Oct 24 19:29:50 2025
InstallationDate: Installed on 2021-11-23 (1431 days ago)
InstallationMedia: Ubuntu 21.10 "Impish Indri" - Release amd64 (20211012)
SourcePackage: gdm3
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.gdm3.custom.conf: 2025-10-24T19:28:32.230086
** Changed in: gdm3 (Ubuntu Noble)
Status: In Progress => Fix Committed
** Changed in: gdm3 (Ubuntu Plucky)
Status: Triaged => Fix Committed
** Changed in: gdm3 (Ubuntu Plucky)
Importance: Undecided => Low
** Changed in: gdm3 (Ubuntu Plucky)
Assignee: (unassigned) => Alessandro Astone (aleasto)
** Changed in: gdm3 (Ubuntu Plucky)
Milestone: None => plucky-updates
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https://bugs.launchpad.net/bugs/2129777
Title:
Automatic Login with latest gdm3 is broken if Wayland doesn't work
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