gdm3/gdm-session-worker crashed with SIGTRAP logging "GdmSession: no session desktop files installed, aborting..." from get_fallback_session_name from get_default_session_name from get_session_name from get_session_filename from gdm_session_is_wayland_session

[Andrew Diete]

https://errors.ubuntu.com/problem/b8e7721d0034b2c4a5ddafcac2e1cc55703f9dbd
https://errors.ubuntu.com/problem/55afdb022e0f09e32692656f5ec80985acf385cc
https://errors.ubuntu.com/problem/f4fce39ac75fb4f87b243f14cb5f8e72f90c2c0f

---

This crash occurs when you uninstall all session files (by accident) from the system. One common way this can happen is by trying to install 'fuse'.

To fix it just run:

  sudo apt install --reinstall ubuntu-session

or whatever-session for your preferred Ubuntu flavor.

[Apport retracing service (apport)]

StacktraceTop:
 get_fallback_session_name (self=self@entry=0x55c1e2529580) at gdm-session.c:593
 get_default_session_name (self=0x55c1e2529580) at gdm-session.c:619
 get_session_name (self=self@entry=0x55c1e2529580) at gdm-session.c:2426
 get_session_filename (self=self@entry=0x55c1e2529580) at gdm-session.c:2999
 gdm_session_is_wayland_session (self=self@entry=0x55c1e2529580) at gdm-session.c:3014

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

I think this looks like the same as:
https://errors.ubuntu.com/problem/b8e7721d0034b2c4a5ddafcac2e1cc55703f9dbd

[Daniel van Vugt (vanvugt)]

Also tracking in:
https://errors.ubuntu.com/problem/55afdb022e0f09e32692656f5ec80985acf385cc

[Daniel van Vugt (vanvugt)]

And now in:
https://errors.ubuntu.com/problem/f4fce39ac75fb4f87b243f14cb5f8e72f90c2c0f

[Yosha872 (yosha)]

I have perhaps a clue, I have a app that stopped working (it was OK 2 weeks ago):

./molotov.AppImage
dlopen(): error loading libfuse.so.2

AppImages require FUSE to run.
You might still be able to extract the contents of this AppImage
if you run it with the --appimage-extract option.
See https://github.com/AppImage/AppImageKit/wiki/FUSE
for more information

But when I try to install FUSE, it asks me to remove ubuntu-session !. I remember that I did that some days/weeks ago.

sudo apt install fuse
Lecture des listes de paquets... Fait
Construction de l'arbre des dépendances... Fait
Lecture des informations d'état... Fait
Le paquet suivant a été installé automatiquement et n'est plus nécessaire :
  xwayland
Veuillez utiliser « sudo apt autoremove » pour le supprimer.
Les paquets supplémentaires suivants seront installés :
  libfuse2
Les paquets suivants seront ENLEVÉS :
  fuse3 ubuntu-session xdg-desktop-portal xdg-desktop-portal-gnome
  xdg-desktop-portal-gtk
Les NOUVEAUX paquets suivants seront installés :
  fuse libfuse2
0 mis à jour, 2 nouvellement installés, 5 à enlever et 0 non mis à jour.
Il est nécessaire de prendre 117 ko dans les archives.
Après cette opération, 1 887 ko d'espace disque seront libérés.
Souhaitez-vous continuer ? [O/n]

[Andrew Diete (adiete-adiete)]

Thanks, that's great.

On Mon, 13 Feb 2023, 11:45 am Daniel van Vugt, <email address hidden>
wrote:

> ** Description changed:
>
>
> https://errors.ubuntu.com/problem/b8e7721d0034b2c4a5ddafcac2e1cc55703f9dbd
>
> https://errors.ubuntu.com/problem/55afdb022e0f09e32692656f5ec80985acf385cc
>
> https://errors.ubuntu.com/problem/f4fce39ac75fb4f87b243f14cb5f8e72f90c2c0f
>
> ---
>
> - multiseat via udev rules not working gdm upset.
> + This crash occurs when you uninstall all session files (by accident)
> + from the system. To fix it just run:
>
> - ProblemType: Crash
> - DistroRelease: Ubuntu 17.10
> - Package: gdm3 3.26.0-1ubuntu1
> - ProcVersionSignature: Ubuntu 4.12.0-13.14-generic 4.12.10
> - Uname: Linux 4.12.0-13-generic x86_64
> - ApportVersion: 2.20.7-0ubuntu1
> - Architecture: amd64
> - CrashCounter: 1
> - Date: Sun Sep 17 18:12:57 2017
> - ExecutablePath: /usr/sbin/gdm3
> - InstallationDate: Installed on 2017-04-09 (161 days ago)
> - InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64
> (20161012.2)
> - ProcCmdline: /usr/sbin/gdm3
> - ProcEnviron:
> - LANG=en_AU.UTF-8
> - LANGUAGE=en_AU:en
> - PATH=(custom, no user)
> - Signal: 5
> - SourcePackage: gdm3
> - StacktraceTop:
> - ()
> - ()
> - ()
> - ()
> - ()
> - Title: gdm3 crashed with signal 5
> - UpgradeStatus: No upgrade log present (probably fresh install)
> - UserGroups:
> + sudo apt install --reinstall ubuntu-session
> +
> + or whatever-session for your preferred Ubuntu flavor.
>
> ** Changed in: gdm3 (Ubuntu)
> Status: Confirmed => Triaged
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1717878
>
> Title:
> gdm3/gdm-session-worker crashed with SIGTRAP logging "GdmSession: no
> session desktop files installed, aborting..." from
> get_fallback_session_name from get_default_session_name from
> get_session_name from get_session_filename from
> gdm_session_is_wayland_session
>
> Status in gdm3 package in Ubuntu:
> Triaged
>
> Bug description:
>
> https://errors.ubuntu.com/problem/b8e7721d0034b2c4a5ddafcac2e1cc55703f9dbd
>
> https://errors.ubuntu.com/problem/55afdb022e0f09e32692656f5ec80985acf385cc
>
> https://errors.ubuntu.com/problem/f4fce39ac75fb4f87b243f14cb5f8e72f90c2c0f
>
> ---
>
> This crash occurs when you uninstall all session files (by accident)
> from the system. To fix it just run:
>
> sudo apt install --reinstall ubuntu-session
>
> or whatever-session for your preferred Ubuntu flavor.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1717878/+subscriptions
>
>

[Paul Arbour (scidhuv00)]

I found the solution worked reinstalling sessions.
I noticed when I did that Apr removed fuse and installed fuse3.
It is likely that installing fuse is the cause of the problem.

[Daniel van Vugt (vanvugt)]

Indeed I expect the real fix would be in 'fuse'. I'm not sure how gdm could be improved here but keep that task open still so people can find the bug.

[Jan Claeys (janc)]

Is there a reason why this 'fuse' package is included and still needed? (I think the libraries packages like 'libfuse2' built from the same source package are still needed, but are the binaries in 'fuse' actually needed?)

It seems like the 'fuse3' package has a "Provides: fuse" line and is installed by default, so 'fuse' should never get installed unless something explicitly asks for it, either with a versioned dependency, or by running "apt install fuse" (or some equivalent of that). And nothing in the archive seems to have such a versioned dependency (at least in "jammy"), so this only really happens when someone installs the 'fuse' package directly.

Someone on IRC just explained that some third party tool said that it needed "fuse", so they did 'sudo apt install fuse' and assumed that that would give them the latest version of "fuse" (which is not entirely unreasonable...), and thus ended up with gdm crashing on next reboot...

Fixing this in stable releases might be tricky, but certainly removing/replacing/renaming 'fuse' should be possible for "noble" at least?

[Andi McClure (andi-mcc)]

I just got trapped by this on Ubunu 23.10. I installed fuse because an explanation of appimage said it depends on fuse and I thought "oh, fuse is good, I should make sure I have fuse installed" and I did not fully read the. An hour later the next time I closed and reopened my laptop lid, my laptop was bricked except for vterms and reboots left me with "[ OK ] Starting gdm service", no gui, and no clearer warning. I was not able to understand what happened until the IRC channel walked me through searching the systemd logs, I got the more full error message and found this bug. I had an online/televideo appointment I missed because my computer was dead for an hour and a half.

It seems to me the *biggest* problem here is that "apt install fuse" should not replace fuse3 with fuse2. I would expect if there's a PACKAGE and a PACKAGE3, that the one with the number is the outdated special version and the un-numbered version is the true one. Certainly not the other way around, that's very, very surprising behavior. I think the case of needing fuse2 is probably rare and an average user would not have the background (I did not) to understand that "installing fuse2" is wrong. Usually when installing a package uninstalls the other package it's because uninstalling the package is harmless (eg because it's an eqivalent). Even if downgrading fuse could be done without breaking the entire GUI, downgrading fuse would probably have undesirable effects and it is far too easy to do by accident.

However also, installing a common package (fuse, whichever version) should not fully break your GUI and it is surprising such a serious gotcha has been present in Ubuntu for six years.

[Andi McClure (andi-mcc)]

Sorry, "did not fully read the" above should be "did not fully read the apt-get console spew".

[InToSSH (intossh)]

I think I did the same thing as @andi-mcc . I ran "apt install fuse" because I found somewhere that it is needed to run the AppImages. I am used to the fact that running the package name with no version means it will install the latest version, as a lot of these packages have an alias for the lastest version.