User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

On Sway (1.6.1) on Manjaro Linux, I drag tabs around windows.

Actual results:

Sometimes, Firefox freezes. I am then unable to kill it even with SIGKILL.

Expected results:

No freezing.

Experiencing the same problem with Firefox 96.0.3 on Sway 1.7; I force-enabled webrender and wayland for Firefox as well.

I used to rearrange tabs by dragging them with the mouse quite often. Every time I try to do that now, it results in a hang. I can't say for sure when it started, but it's started in the past few weeks; I upgraded to 96 on Jan 11th, and have been updating the minor versions since; the 96 version upgrade is likely to blame.

More than happy to provide more details if this is hard to reproduce. I'm even willing to jump on a call and screenshare to help debug this :)

Can you try with mutter/kde?
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Testing_different_Wayland_compositor
Thanks.

That's a good tip, thanks! I can confirm I cannot reproduce on Mutter. I tried searching in the sway and wlroots issue trackers for anything recent related to Firefox hangs, but found nothing.

Err, I just realised that Firefox on Sway doesn't always reproduce, either. I'm now having trouble reproducing again. So maybe the bug does happen on Mutter, I'm not sure. I need to find some way to reliably reproduce first.

The thing is it happens pretty sporadically and unfortunately I can't seem to find a way to reproduce the hang consistently.

I have found that I can actually kill Firefox. It does not work with either pkill firefox nor pkill -9 firefox, but killall /usr/lib/firefox/firefox does kill it, so I can at the very least continue using my computer without rebooting.

Is there perhaps some kind of debug logging feature that I could enable so that I can send over a log when the hang happens?

Hi! I've been encountering this issue on Gnome (mutter) sporadically as well. (fedora 35, gnome 41.3, firefox --full-version
Mozilla Firefox 96.0 20220111210158 20220111210158). (I'm using Firefox from the Fedora dnf repos.) I should also mention that in the about:config, gfx.webrender.all is set to true and I'm also using Wayland.

Firefox 96.0.3 is available in dnf, but I haven't updated to that yet.

This seems like a duplicate of bug 1754789, which appears to have been fixed in hg.

The bug has a release status flag that shows some version of Firefox is affected, thus it will be considered confirmed.

This hasn't happened in a while for me, it may have actually been fixed together with bug 1754789 (I'm currently on version 100.0.2).

Thanks.