Bug 496712 - Taskmanager crashes repeatedly after trying to render a window preview (caused by mouse hover over LibreWolf, system settings, etc.)
Summary: Taskmanager crashes repeatedly after trying to render a window preview (cause...
Status: RESOLVED FIXED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Task Manager and Icons-Only Task Manager widgets (show other bugs)
Version: 5.27.11
Platform: Debian stable Linux
: NOR crash
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-11-26 16:55 UTC by Kryštof Jelínek
Modified: 2024-11-26 21:41 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In: 6.0.0
Sentry Crash Report:


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Description Kryštof Jelínek 2024-11-26 16:55:09 UTC
SUMMARY
Taskmanager ("classic taskbar-style window switcher displaying icons and text") repeatedly crashes after I hover over open windows. It does not matter what application window I hover over, but the issue is mainly triggered by hovering over Firefox / LibreWolf, although not exclusively.


STEPS TO REPRODUCE
1. Set-up the classic taskbar widget
2. Enable the preview window when hovering over tasks option
3. Panel crashes after hovering over web browser tasks (after a short while)


OBSERVED RESULT
Whole Plasma environment stops responding. Already running tasks are usable and respond, but the desktop environment itself dies off.

The crash is recoverable by executing killall plasmashell; nohup plasmashell &
but this is unusable for most users.

EXPECTED RESULT
Panel not to crash.

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux 12
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.15
Kernel Version: 6.11.7-amd64 (64-bit)
Graphics Platform: Wayland *Happens on X11 as well
Comment 1 Nate Graham 2024-11-26 17:02:49 UTC
If something crashed, we need a backtrace of it so we can figure out what's going on. Can you please attach a backtrace of the crash using the `coredumpctl` command-line program, as detailed in https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl?

Thanks
Comment 2 Kryštof Jelínek 2024-11-26 17:39:43 UTC
(In reply to Nate Graham from comment #1)
> If something crashed, we need a backtrace of it so we can figure out what's
> going on. Can you please attach a backtrace of the crash using the
> `coredumpctl` command-line program, as detailed in
> https://community.kde.org/Guidelines_and_HOWTOs/Debugging/
> How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl?
> 
> Thanks

(In reply to Nate Graham from comment #1)
> If something crashed, we need a backtrace of it so we can figure out what's
> going on. Can you please attach a backtrace of the crash using the
> `coredumpctl` command-line program, as detailed in
> https://community.kde.org/Guidelines_and_HOWTOs/Debugging/
> How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl?
> 
> Thanks

OK, poor wording on my side - it does not crash per se. I've checked coredumps and there are no corresponding records for this error. There were a few occasions with Plasma restarting automatically after about an hour of being frozen, but I can't surely say which backtraces are tied to this.

So to put it correctly (and I'm sorry for not doing so beforehand): Plasma freezes - does not crash, but visually gets completely stuck (the clock stops, animations stop, all task updates stop). I can even click on the system tray or switch windows from the taskbar, but I have to remember the positioning of elements...

Is there any way I could provide more error info? Because I do not know how to make it crash... I've just frozen it again by hovering over tasks and I will try to see if it restarts automatically. Maybe then we will get a new coredump?
Comment 3 Nate Graham 2024-11-26 21:37:24 UTC
Ok, so a freeze but not a crash. Well, good news and bad news:
1. Good news: this is fixed in Plasma 6!
2. Bad news: you're using Debian which ships an ancient version of Plasma, and even if we found the exact thing that fixes it and backported it, Debian wouldn't take it.

I'm afraid you'll have to wait until Debian ships Plasma 6, switch distros, or look for a workaround.
Comment 4 Kryštof Jelínek 2024-11-26 21:41:09 UTC
(In reply to Nate Graham from comment #3)
> Ok, so a freeze but not a crash. Well, good news and bad news:
> 1. Good news: this is fixed in Plasma 6!
> 2. Bad news: you're using Debian which ships an ancient version of Plasma,
> and even if we found the exact thing that fixes it and backported it, Debian
> wouldn't take it.
> 
> I'm afraid you'll have to wait until Debian ships Plasma 6, switch distros,
> or look for a workaround.

OK, thank you for info!