!xcb_xlib_threads_sequence_lost error with GTK2 applications

Bug #1808710 reported by Ilya Kotov on 2018-12-16
This bug affects 4 people
Affects Status Importance Assigned to Milestone
gtk+2.0 (Ubuntu)

Bug Description

GTK2 applications randomly crash or freeze with error like:

[xcb] Unknown sequence number while processing queue
[xcb] Most likely this is a multi-threaded client and XInitThreads has not been called
[xcb] Aborting, sorry about that.
<application>: ../../src/xcb_io.c:263: poll_for_event: Assertion `!xcb_xlib_threads_sequence_lost' failed.

where <application> is the name of the executable, e.g. audacious, soffice.bin, etc.

LibreOffice: https://bugs.launchpad.net/ubuntu/+source/libreoffice/+bug/1801161
PCManFM: https://bugs.launchpad.net/ubuntu/+source/pcmanfm/+bug/1782984
Audacious: https://redmine.audacious-media-player.org/issues/798
FreeCAD: https://bugs.launchpad.net/ubuntu/+source/freecad/+bug/1754084
ClawsMail: https://www.thewildbeast.co.uk/claws-mail/bugzilla/show_bug.cgi?id=4203

SpaceFM, Pidgin, GPicView and GIMP appear to have similar problems.

Ilya Kotov (forkotov02) wrote :
Ilya Kotov (forkotov02) wrote :
Ilya Kotov (forkotov02) wrote :
affects: freecad (Ubuntu) → gtk+2.0 (Ubuntu)
Ilya Kotov (forkotov02) on 2018-12-18
description: updated
Launchpad Janitor (janitor) wrote :

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

Changed in gtk+2.0 (Ubuntu):
status: New → Confirmed
Walter Lapchynski (wxl) on 2019-04-07
summary: - !xcb_xlib_threads_sequence_lost error
+ !xcb_xlib_threads_sequence_lost error with GTK2 applications
Walter Lapchynski (wxl) on 2019-04-07
description: updated
Changed in gtk+2.0 (Ubuntu):
importance: Undecided → Critical
Alex Fedorov (fedorov-ao) wrote :

Apparently, same bug for Audacious media player: https://redmine.audacious-media-player.org/issues/798 .

Also, Freecad users have encountered the similar error and managed to bypass is by setting LIBGL_DRI3_DISABLE environment variable to true before running Freecad: https://bugs.launchpad.net/ubuntu/+source/freecad/+bug/1754084/comments/13

Alex Fedorov (fedorov-ao) wrote :

Unfortunately, setting LIBGL_DRI3_DISABLE to true did not help to bypass the bug.

On the other hand, the bug does not manifest itself if there is only one active CPU core. The number of active CPU cores can be controlled by 'maxcpus' kernel parameter: add 'maxcpus=1' to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub, then run update-grub as root.

Walter Lapchynski (wxl) wrote :

Looks like there's an upstream bug against Claws Mail, too:

Walter Lapchynski (wxl) on 2019-05-05
description: updated
description: updated
Peter S (guestsdfg) wrote :

I have the same problem with eboard 1.1.3 on Debian Buster. The program build is quite old (2016), hence it seems that the problem is with some high-level library.

John Sweeney (john-sweeney) wrote :

I have the same problem with audacious, on UbuntuStudio 18.04

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