ubuntu 24.04 installer crash

After getting to the "Choose location" for the timezone selection, the installer crashes.

installer crashes at the end.

Thank you for your bug report, could you attach the content of /var/log/installer?

This seems to happen at any point during the installer, I noticed this in logs at the time of crash:

[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.
ubuntu_bootstrap: ../../src/xcb_io.c:278: poll_for_event: Assertion `!xcb_xlib_threads_sequence_lost' failed.
Aborted (core dumped)

Would defaulting to Wayland for the installer fix this?

Installer log attached

The 2024-04-18 installer gui seems to crash randomly, whether using an auto install script or installing interactively. The most interesting thing is that the installation continues in the background, without the gui. For example. If it is rsyncing the filesystem that command continues. Apport does not offer to upload any documentation. I've seen this crash several times today and it is fairly reliable show stopper release critical bug. How can I help resolve this issue? Is there a more pertinent bug report than this one?

it's unclear those are the same issue, could everyone open separate reports, preferably using 'ubuntu-bug ubuntu-desktop-bootstrap' or manually adding an archive of /var/log/installer and `journalctl > journal` after getting the issue?

I had a similar problem several times when installing Ubuntu Budgie, where the Installer Window would just disappear at some point while I was answering the setup questions.

However, a workaround that seems to have worked for many in the r/Ubuntu subreddit (not Ubuntu-Budgie-specific, and which also worked for me) is to start the Live Session in safe graphics mode.

Hoping that helps to narrow things down.

BTW, at this point I don't have a valid crash log because of the aforementioned successful installation while running the Live Session in safe graphics mode.

I am seeing possibly the same crash using xubuntu-24.04-desktop-amd64.iso, the installer crashes at seemingly random times with the same error message as above:

[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.
ubuntu_bootstrap: ../../src/xcb_io.c:278: poll_for_event: Assertion `!xcb_xlib_threads_sequence_lost' failed.
Aborted (core dumped)

I've observed it all four times I've tried to run it so far from the Xubuntu Live session, first time was just after the keyboard layout selection (wasn't running in terminal so didn't see error message on this one), last three times were on the partition selection (under Manual Installation).
> preferably using 'ubuntu-bug ubuntu-desktop-bootstrap'

This gives an error message "The problem cannot be reported: ubuntu-desktop-bootstrap is provided by a snap published by canonical. No contact address has been provided; visit the forum at https://forum.snapcraft.io/ for help."

I do have my /var/log/installer archive and `journalctl > journal.txt` from earlier in this live session though (IIRC after three crashes). Note that none of these files appear to include the xcb error message.

I saw that there's an updated `ubuntu-desktop-bootstrap` snap on the candidate channel, I tried using that and I got a possibly different crash the first time (didn't see any error message, it just exited), but the second time I saw the same xcb error as above.

I'll try rebooting and selecting safe graphics to see if that helps.

Update: I ran with nomodeset and did not encounter the crash, unsure if that's related or I just got lucky.

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

Jun 16 12:42:09 ubuntu subiquity_log.3731[6488]: finish: cmd-in-target: FAIL: curtin command in-target
Jun 16 12:42:09 ubuntu subiquity_event.3731[3731]: configuring apt
Jun 16 12:42:09 ubuntu subiquity_event.3731[3731]:
Jun 16 12:42:09 ubuntu subiquity_event.3731[3731]: curtin command in-target

After this the installation crashed and says System program problem detected