Xorg crashed with SIGSEGV in mieqEnqueue() from queueEventList() from QueueKeyboardEvents() from xf86PostKeyEventM() from xf86PostKeyboardEvent()

[errors.ubuntu.com bug bridge]

The Ubuntu Error Tracker has been receiving reports about a problem regarding xorg-server. This problem was most recently seen with package version 2:1.20.13-1ubuntu1~20.04.2, the problem page at https://errors.ubuntu.com/problem/0d919d402b708884960b8624a96c568ee5357955 contains more details, including versions of packages affected, stacktrace or traceback, and individual crash reports.
If you do not have access to the Ubuntu Error Tracker and are a software developer, you can request it at http://forms.canonical.com/reports/.

[Launchpad Janitor (janitor)]

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

[Daniel van Vugt (vanvugt)]

This crash appears to be so rare that I can't tell if it was fixed after 20.04 or just too uncommon to be reported yet in newer releases.

[Lars Rune Præstmark (lars-rune-praestmark)]

Possibly fixed after 20.04? I might try upgrading some day I have plenty of time then. If I then stop getting the crashes, I could mention that here. And if I still get them, I guess I could mention that. It's pretty random when it happens, but I guess it should happen at least once per month, especially if I type a lot or install certain Plover plugins (system switcher and VLC commands).

[Lars Rune Præstmark (lars-rune-praestmark)]

I upgraded to 21.10 yesterday, but haven't used it long enough to know for sure if the crash also happens here. And it switched to Wayland, which doesn't really solve the problem, since Plover isn't currently compatible with it. But I switched to Xorg and haven't got any Xorg crashes on 21.10 so far.

However I did get another bug, which I'm not sure which package is in. Sometimes a word or phrase written with a single chord on the keyboard will come out with some characters missing, or backspacing gets messed up. This seems to be happening only with charcters that appear several times in the thing I'm writing, so if I write "teen princess", it might get turned into "ten princes" with the repeated e and s removed. Teen teen teen teen teen teen teen teen teen teen teen teen teen teen teen teen teen. Well, I guess it's not happening right now, at least on that word. There are there are there are ther are there are. Well, one of the there's got an e to little, so that's the type of issue. Where would I report that? It happens when I use Plover, but when I try to check what Plover is trying to outpt, it's sending the right keypresses, so it's something that processes them later tha's getting rid of some characters.

[Lars Rune Præstmark (lars-rune-praestmark)]

Still less than twenty-four hours since the upgrade, still no crashes after it. But I found a workaround for the missing characters bug. Just switch to the Lubuntu desktop instead of the (GNOME) Ubuntu one. Might still want to report that bug to IBus or Xorg or whatever was causing the keypresses to get lost. So if you know how to figure out which package I should be reporting it about, that would be nice.

[Lars Rune Præstmark (lars-rune-praestmark)]

Today I got sent back to the login screen in the same way, same symptoms, same circumstances as last time (writing text into Firefox using Plover), and this is after upgrading to 21.10. However, I can't see a crash file from Xorg, only a _usr_bin_lxqt-panel.1000.crash. This time I was using the Lubuntu desktop rather than the (GNOME) Ubuntu one where I had been getting a different bug that made it look like I made a bunch of typos.

[Lars Rune Præstmark (lars-rune-praestmark)]

I tried to use the Plasma (x11) desktop (installed the kubuntu-desktop package) and I got the crash there too, and I think I already mentioned it happen on GNOME (Ubuntu, manually installed the ubuntu-desktop package) and LXQt (Lubuntu). Well, someone else seems to have got a crash under similar circumstances but using KDE on Manjaro, and for them Xorg actually logged some error messages. And they reported it to Plover: https://github.com/openstenoproject/plover/issues/1479 I'm aware that Manjaro might have a slightly different version of Xorg, but I figured it was worth mentioning that this has happened to someone on another distro too, and that unlike me they got this in the Xorg logs:
[ 14208.301] (EE) Segmentation fault at address 0x7ffd98866000
in case that helps with anything.

[Lars Rune Præstmark (lars-rune-praestmark)]

It happened again, this time on the Lubuntu desktop, and this time I'm pretty sure there was a crash file with "xorg" in the name, but running ubuntu-bug might just have renamed it without sending anything... Anyway, it seems it wasn't the only thing that crashed, so might as well give you the link to the error report that does appear to have got sent: https://errors.ubuntu.com/oops/2138bbc8-8b76-11ec-87d9-fa163e6cac46

That probably doesn't help a lot. But yeah, mentioning that something else seems to have crashed at the same time seems like the type of thing that probably doesn't matter but maybe it does. I've also heard from another person who got the crash today, not sure if that was on Ubuntu or something else (I do hope distributions have some coordination rather than fixing the bugs independently of each other, but I've started to wonder if they do).

If it is getting annoying that I tell you every time I notice anything new, it's okay to tell me to stop.

[Lars Rune Præstmark (lars-rune-praestmark)]

For a while I stopped using Plover to avoid this issue, then I tried using it again and nothing crashed. After using it more times and Xorg still not crashing I think the bug seems to at least have stopped affecting me.