Logged out when unplugging external monitors with screen locked and lid closed

[Jonathan Kamens]

I am using Ubuntu 18.04 (Bionic) 64-bit on a System76 Galaga UltraPro laptop. At work, I plug two displays into my laptop, one DisplayPort and one HDMI.

If, while both displays are plugged in and the laptop lid is closed and the laptop's built-in display is therefore disabled, I:

1. lock my screen;
2. unplug both displays at about the same time;
3. wait about ten seconds; and then
4. open my laptop lid,

I find that I have been logged out.

If I immediately log back in to the built-in display, a couple seconds after I log in, the screen locks. If I then immediately log out and log back in again, the screen does _not_ lock.

It seems that this weird lock-right-after-login behavior is related to the fact that I get logged out as described above. It seems that the shell remembers that it is supposed to be locked despite the crash / logout, such that when I log back in, it realizes that it's supposed to be locked and locks itself.

Note that I am filing this bug as instructed in https://bugs.launchpad.net/gnome-shell/+bug/1721428/comments/105: "BTW, we have fixed many gnome-shell bugs with these symptoms recently in Ubuntu 18.04. So please try 18.04 and log a new bug if you have any problems."

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-shell 3.28.1-0ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon May 7 14:26:22 2018
DisplayManager: gdm3
InstallationDate: Installed on 2016-08-09 (635 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to bionic on 2018-04-27 (10 days ago)

[Daniel van Vugt (vanvugt)]

Sounds like a crash is occurring, and we have indeed encountered a few reports like this.

To proceed with finding out which crash this is, please:

1. Apply the workaround from bug 994921.

2. Reproduce the crash.

3. Look in /var/crash for crash files and run:
   ubuntu-bug /var/crash/YOURFILE.crash

4. Tell us here the ID of the new bug created.

[Jonathan Kamens (jik)]

https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1769982

[Jonathan Kamens (jik)]

Note that there are crashes around the same time in /usr/lib/hidpi-daemon/hidpi-daemon and /usr/lib/hidpi-daemon/hidpi-notification, which are provided by System76, but looking at the dumps in /var/crash for them, it looks like they are crashing _as a result of_ the gnome-shell crash, as opposed to because of it.

The hidpi-daemon crash says this:

 GLib.GError: g-dbus-error-quark: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying (4)

which I _think_ means it was trying to message gnome-shell and failed because the shell had crashed. And the hidpi-notification crash says this:

Title: hidpi-notification crashed with GLib.GError in get(): g-dbus-error-quark: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name com.system76.hidpi was not provided by any .service files (2)

which I think means that it crashed because hidpi-daemon crashed.

[Daniel van Vugt (vanvugt)]

Thanks. Let's track this in bug 1723615 then.

If you find more crash files then please continue to report them using 'ubuntu-bug' and the robots will hopefully be able to analyse those and tell you what each one is.