Bug 508874

Summary: KWin crashes when waking from sleep
Product: [Plasma] kwin Reporter: Reid Swanson <reid>
Component: generic-crashAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED BACKTRACE    
Severity: crash CC: kde
Priority: NOR    
Version First Reported In: 6.4.4   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: The system log containing statements just before and after sleeping

Description Reid Swanson 2025-08-28 21:32:28 UTC
Created attachment 184541 [details]
The system log containing statements just before and after sleeping

SUMMARY
After a recent system update KWin crashes every time I wake from sleep. KWin is able to reopen many of the closed applications, but it fails to reopen non-native KDE applications. For example, it will not reopen Firefox, Thunderbird, VSCode. Most windows get opened on my primary monitor (out of 3), but some are opened on other monitors and it doesn't seem to have any relation to which monitor they were on before the crash. Also, since this is Wayland, all the windows get placed on one of my virtual desktops and I must manually move them back to where they belong.

I have filed numerous automatic crash reports, but I have no idea where they go or how to associate them with this ticket.

STEPS TO REPRODUCE
1. Put the system to sleep (either manually or automatically).
2. Wake the system up

OBSERVED RESULT
KWin reports a crash and some applications/windows are restarted while others are not.


EXPECTED RESULT
KWin should not crash and my applications/windows should be where I left them.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma:  Arch Linux
KDE Plasma Version: 6.4.4
KDE Frameworks Version:  6.17.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION
I've attached the tail of my journalctl log that hopefully has some useful information.
Comment 1 David Edmundson 2025-08-29 08:47:43 UTC
The important part of the log is the backtrace:

            #2  0x00007f214c2e6e97 _ZN6KCrash19defaultCrashHandlerEi (libKF6Crash.so.6 + 0x7e97)
                                                 #3  0x00007f214863e540 n/a (libc.so.6 + 0x3e540)
                                                 #4  0x00007f214befd763 n/a (libkwin.so.6 + 0x4fd763)
                                                 #5  0x00007f214744bac6 n/a (libffi.so.8 + 0x7ac6)
                                                 #6  0x00007f214744876b n/a (libffi.so.8 + 0x476b)

which unfortunately is missing all symbols. There is nothing we can action in this report. 
Please either install debug symbols for kwin or hopefully we will resolve this via another user.

>I have filed numerous automatic crash reports, but I have no idea where they go or how to associate them with this ticket.

we'll find them there.
Comment 2 Reid Swanson 2025-08-29 16:47:42 UTC
(In reply to David Edmundson from comment #1)
> The important part of the log is the backtrace:
> 
>             #2  0x00007f214c2e6e97 _ZN6KCrash19defaultCrashHandlerEi
> (libKF6Crash.so.6 + 0x7e97)
>                                                  #3  0x00007f214863e540 n/a
> (libc.so.6 + 0x3e540)
>                                                  #4  0x00007f214befd763 n/a
> (libkwin.so.6 + 0x4fd763)
>                                                  #5  0x00007f214744bac6 n/a
> (libffi.so.8 + 0x7ac6)
>                                                  #6  0x00007f214744876b n/a
> (libffi.so.8 + 0x476b)
> 
> which unfortunately is missing all symbols. There is nothing we can action
> in this report. 
> Please either install debug symbols for kwin or hopefully we will resolve
> this via another user.
> 
> >I have filed numerous automatic crash reports, but I have no idea where they go or how to associate them with this ticket.
> 
> we'll find them there.

I'd be happy to upload the core dump, but it exceeds the maximum file size for attachments. The instructions for installing debug symbols for kwin on the ArchWiki are not clear to me. Otherwise, I'd be happy to do that too, but recompiling kwin and overriding the package version is probably not feasible on my end.