Arch Linux

Please read this before reporting a bug:

Do NOT report bugs when a package is just outdated, or it is in the AUR. Use the 'flag out of date' link on the package page, or the Mailing List.

REPEAT: Do NOT report bugs for outdated packages!

FS#76669 - [libx11] Firefox unresponsive on copying or pasting

Attached to Project: Arch Linux
Opened by Karthik (wpd) - Friday, 25 November 2022, 14:47 GMT
Last edited by Andreas Radke (AndyRTR) - Sunday, 18 December 2022, 20:45 GMT
Task Type Bug Report
Category Packages: Extra
Status Closed
Assigned To Andreas Radke (AndyRTR)
Architecture All
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 6
Private No


Randomly selecting, copying and pasting text on webpages makes firefox freeze permanently with libx11 1.8.2-2. When I downgrade to 1.8.1-3, this problem goes away

Upstream bug:
This task depends upon

Closed by  Andreas Radke (AndyRTR)
Sunday, 18 December 2022, 20:45 GMT
Reason for closing:  Fixed
Comment by Toolybird (Toolybird) - Friday, 25 November 2022, 22:32 GMT
Key bit of info missing from this report but included in the upstream report:

"I am running KDE on ArchLinux with the latest versions of packages on Nvidia 1660"

Someone needs to report this upstream to Xorg devs. FWIW, I cannot repro on my normal setup but will attempt to in a VM.
Comment by Toolybird (Toolybird) - Saturday, 26 November 2022, 20:51 GMT Comment by Sven-Hendrik Haase (Svenstaro) - Saturday, 03 December 2022, 22:34 GMT
FWIW I can confirm this - it's super annoying, too!
Comment by Andreas Radke (AndyRTR) - Friday, 16 December 2022, 14:38 GMT
Please check libx11 1.8.3-1.
Comment by Guilherme (GUiHKX) - Friday, 16 December 2022, 20:42 GMT
No, 1.8.3-1 didn't make a difference for me. I'm attaching a gdb backtrace of Firefox in the frozen state.

The issue is also (sometimes) reproducible just by opening Firefox's "Downloads" window.

The upstream libx11 issue is this one:

According to a comment by @rockybulwinkle on the thread above, this problem was introduced by commit 79775575418fd6f8ee1c5e5bbe403df4606fb5b6, so reverting it might actually fix the problem.

At least I've been using this AUR package ( that just reverts the commit and I haven't experienced the freeze/crash, yet.
Comment by Gian Andrea (gkun) - Saturday, 17 December 2022, 10:05 GMT
Using the arch package in the previous comment also fixed a random crash I was experiencing in gzdoom (crash was on no response to xcb_request_check).
Comment by member007 (member007) - Saturday, 17 December 2022, 11:20 GMT
The frequent freezing has turned into (less?) frequent crashing. This is an improvement as I can resume quicker, but it's still obviously a big problem. I also get a dump in the journalctl when Firefox crashes. You don't get a dump when Firefox freezes. Here is the latest crash:

Dec 17 11:00:08 **** systemd[1479]: app-gnome-firefox-2689.scope: Consumed 16min 39.745s CPU time.
Dec 17 11:00:08 **** firefox.desktop[5638]: Exiting due to channel error.
Dec 17 11:00:08 **** firefox.desktop[5553]: Exiting due to channel error.
Dec 17 11:00:08 **** firefox.desktop[5392]: Exiting due to channel error.
Dec 17 11:00:08 **** firefox.desktop[6003]: Exiting due to channel error.
Dec 17 11:00:08 **** firefox.desktop[5596]: Exiting due to channel error.
Dec 17 11:00:08 **** firefox.desktop[2689]: firefox: xcb_io.c:175: dequeue_pending_request: Assertion `!xcb_xlib_unknown_req_in_deq' failed.
Dec 17 11:00:08 **** firefox.desktop[2689]: [xcb] Aborting, sorry about that.
Dec 17 11:00:08 **** firefox.desktop[2689]: [xcb] You called XInitThreads, this is not your fault
Dec 17 11:00:08 **** firefox.desktop[2689]: [xcb] Unknown request in queue while dequeuing

Note the above is in reverse order with "journalctl -r". The oldest message is at the bottom.

I feel like the crashing is somehow less frequent than the freezing, but I haven't measured this. For years, until about a month ago Firefox very rarely, if ever, crashed.
Comment by Andreas Radke (AndyRTR) - Saturday, 17 December 2022, 22:47 GMT
Please try 1.8.3-2 from testing repo.
Comment by Guilherme (GUiHKX) - Sunday, 18 December 2022, 17:26 GMT
1.8.3-2 seems to have fixed it for me.