Ubuntu 18.04 interface freeze - during video call or screen sharing (using Slack or Zoom)

[Nikolay Kirilov]

I'm using Ubuntu 18.04 (bionic) GNOME 3.28.2 .15.0-45-generic
Since some updates in the last 2 weeks the interface started to freeze for 15-20 seconds and then reloads (like a crash of the UI, then it got killed by the OS, and then restarted).

The computer is unusable for 15-20 seconds then it works as nothing happened (I got proper sound and I believe everything is working - I just don't see it and I can not interact).

I updated again and again (with the hope it's something terrible that affected a lot of users and is already fixed, but looks it's not).

I started observing the problem more closely:
The logs app that comes with Ubuntu shows this error (under System section) at similar times the interface crashes:

gnome-shell[22505]: segfault at 28 ip 00007f9a80434fe0 sp 00007ffd7fb8b058 error 4 in libmutter-2.so.0.0.0[7f9a803b1000+157000]

gnome-shell[3366]: segfault at 28 ip 00007ffa74598fe0 sp 00007ffc912713c8 error 4 in libmutter-2.so.0.0.0[7ffa74515000+157000]

The problem appears in most cases when I'm on a video call using Slack or Zoom, so probably be related to that (not sure is it limited to that actually - may be it happened even when I was not on a call).
I heavily use multiple desktops and switch between them very often (on a single TFT display).

I'll be glad if anyone has an idea how to resolve this or report it (without reinstalling, which actually may be faster and easier).

Thanks
NK

[Nikolay Kirilov (kirilovnv)]

Looks the issue appears when I'm on a video / screen sharing call and I switch between desktops.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1817682/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It sounds like some part of the system has crashed. To help us find the cause of the crash please follow these steps:

1. Look in /var/crash for crash files and if found run:
    ubuntu-bug YOURFILE.crash
Then tell us the ID of the newly-created bug.

2. If step 1 failed then look at https://errors.ubuntu.com/user/ID where ID is the content of file /var/lib/whoopsie/whoopsie-id on the machine. Do you find any links to recent problems on that page? If so then please send the links to us.

3. If step 2 also failed then apply the workaround from bug 994921, reboot, reproduce the crash, and retry step 1.

Please take care to avoid attaching .crash files to bugs as we are unable to process them as file attachments. It would also be a security risk for yourself.

[Daniel van Vugt (vanvugt)]

This sounds like it might be bug 1754693. But still, please follow the steps above.

[Nikolay Kirilov (kirilovnv)]

Hi, Dan,
thanks for your suggestions.
Unfortunately step 1 and 2 failed.
Then I applied the workaround from step 3, restarted, crashed the UI and retried 1 and 2
Looks there is no difference - no crash files and nothing for my user in errors.ubuntu.com/user

If you have any other suggestions let me know.

Thanks for your support.

[Daniel van Vugt (vanvugt)]

OK. My best guess is still bug 1754693, which doesn't yet have an 18.04 fix.

In the meantime, please:

 * Ensure you have no gnome-shell extensions installed (except for the two default Ubuntu ones). Please uninstall all others and tell us if that fixes the problem.

 * Attach a full copy of the log mentioning "gnome-shell[22505]: segfault" etc.

[Nikolay Kirilov (kirilovnv)]

A possible workaround is to just stop using multiple workspaces (put everything on the default one) and don't switch between them.

From my point of view a developer should easily reproduce that crash. I believe the steps to reproduce are pretty clear.

Thanks for your support Daniel - I'll stick to the workaround (even though it's pretty disappointing).

[Daniel van Vugt (vanvugt)]

If the problem relates to workspace switching in 18.04 then there's also a good chance that this is bug 1812527.

Sorry I am unable to reproduce any such problems here, yet.

[Daniel van Vugt (vanvugt)]

Please:

1. Reproduce the problem.

2. Reboot.

3. Run: journalctl -b-1 > prevboot.txt

4. Attach the file 'prevboot.txt' to this bug.

[Jonas Stenberg (jonas-stenberg)]

I have exactly the same problem but it only happens when I talk to people that uses Windows on their desktop. I attached a section of my syslog where this happened.

[Daniel van Vugt (vanvugt)]

Jonas, that is bug 1812527 you have. Please comment in bug 1812527 instead.

[Jonas Stenberg (jonas-stenberg)]

Re-pasting attachment cleaned from sensitive data.

[Daniel van Vugt (vanvugt)]

Jonas, that is bug 1812527 you have. Please comment in bug 1812527 instead.

[Daniel van Vugt (vanvugt)]

Nikolay,

Please follow the steps in comment #9.

[Launchpad Janitor (janitor)]

[Expired for gnome-shell (Ubuntu) because there has been no activity for 60 days.]