Unfortunately the backtrace is lacking debug symbols. Please install the debug packages for at least KWin and attach a new backtrace.

Finally! It happened again, and now I have a backtrace.

I'm using sddm with plasma desktop (on debian sid).

If I turn the machine on, and leave it for ~10 minutes, only then I log in - it crashes.

Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
[Current thread is 1 (Thread 0x7f5dcf0c3940 (LWP 2079))]

Thread 5 (Thread 0x7f5dc4dbe700 (LWP 2121)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f5de38642c4 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7f5de394df20 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007f5de3864309 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007f5de0538494 in start_thread (arg=0x7f5dc4dbe700) at pthread_create.c:333
#4  0x00007f5de681a93f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 4 (Thread 0x7f5dc69d0700 (LWP 2095)):
[KCrash Handler]
#6  QRingBuffer::chop (this=0x0, bytes=14989) at tools/qringbuffer.cpp:178
#7  0x00007f5de45cc5b6 in QIODevicePrivate::QRingBufferRef::chop (bytes=14989, this=<optimized out>) at io/qiodevice_p.h:102
#8  QIODevice::read (this=this@entry=0x558b7c3cfc48, data=0x7f5db800dab8 "\220\332", maxSize=maxSize@entry=1395) at io/qiodevice.cpp:1078
#9  0x00007f5de45ccc37 in QIODevice::readAll (this=this@entry=0x558b7c3cfc48) at io/qiodevice.cpp:1235
#10 0x00007f5de641822b in KWin::Script::loadScriptFromFile (this=<optimized out>) at ./scripting/scripting.cpp:460
#11 0x00007f5de6419622 in QtConcurrent::StoredMemberFunctionPointerCall0<QByteArray, KWin::Script>::runFunctor (this=0x558b7c3ffcc0) at /usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentstoredfunctioncall.h:189
#12 QtConcurrent::RunFunctionTask<QByteArray>::run (this=0x558b7c3ffcc0) at /usr/include/x86_64-linux-gnu/qt5/QtConcurrent/qtconcurrentrunbase.h:108
#13 0x00007f5de44cd14f in QThreadPoolThread::run (this=0x558b7c31a840) at thread/qthreadpool.cpp:99
#14 0x00007f5de44d0da8 in QThreadPrivate::start (arg=0x558b7c31a840) at thread/qthread_unix.cpp:368
#15 0x00007f5de0538494 in start_thread (arg=0x7f5dc69d0700) at pthread_create.c:333
#16 0x00007f5de681a93f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 3 (Thread 0x7f5dc7fff700 (LWP 2093)):
#0  0x00007f5de68115b1 in __GI_ppoll (fds=fds@entry=0x7f5dc000ab18, nfds=nfds@entry=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f5de46f0391 in ppoll (__ss=<optimized out>, __timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:77
#2  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f5dc000ab18) at kernel/qcore_unix.cpp:81
#3  qt_safe_poll (fds=0x7f5dc000ab18, nfds=1, timeout_ts=timeout_ts@entry=0x0) at kernel/qcore_unix.cpp:102
#4  0x00007f5de46f1c8a in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:500
#5  0x00007f5de469e9ca in QEventLoop::exec (this=this@entry=0x7f5dc7ffec50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#6  0x00007f5de44cc0f3 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:507
#7  0x00007f5de6e116d5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#8  0x00007f5de44d0da8 in QThreadPrivate::start (arg=0x7f5de6e86d60) at thread/qthread_unix.cpp:368
#9  0x00007f5de0538494 in start_thread (arg=0x7f5dc7fff700) at pthread_create.c:333
#10 0x00007f5de681a93f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 2 (Thread 0x7f5dce12a700 (LWP 2091)):
#0  0x00007f5de68114ed in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f5de597c150 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f5de597dee9 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f5dcedd4b69 in QXcbEventReader::run (this=0x558b7c2823b0) at qxcbconnection.cpp:1343
#4  0x00007f5de44d0da8 in QThreadPrivate::start (arg=0x558b7c2823b0) at thread/qthread_unix.cpp:368
#5  0x00007f5de0538494 in start_thread (arg=0x7f5dce12a700) at pthread_create.c:333
#6  0x00007f5de681a93f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 1 (Thread 0x7f5dcf0c3940 (LWP 2079)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f5de44d1c6b in QWaitConditionPrivate::wait (time=18446744073709551615, this=0x558b7c31d6d0) at thread/qwaitcondition_unix.cpp:143
#2  QWaitCondition::wait (this=this@entry=0x558b7c31fee8, mutex=mutex@entry=0x558b7c31fec0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:215
#3  0x00007f5de44cc8a2 in QThreadPoolPrivate::waitForDone (this=this@entry=0x558b7c31fe50, msecs=msecs@entry=-1) at thread/qthreadpool.cpp:293
#4  0x00007f5de44ccca1 in QThreadPool::waitForDone (this=<optimized out>, msecs=msecs@entry=-1) at thread/qthreadpool.cpp:623
#5  0x00007f5de46a2425 in QCoreApplication::~QCoreApplication (this=0x7fff48fe6fd0, __in_chrg=<optimized out>) at kernel/qcoreapplication.cpp:840
#6  0x00007f5de4f84601 in QApplication::~QApplication (this=0x7fff48fe6fd0, __in_chrg=<optimized out>) at kernel/qapplication.cpp:825
#7  0x00007f5de6ad7984 in ?? () from /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#8  0x00007f5de6ad9216 in kdemain () from /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#9  0x00007f5de67522b1 in __libc_start_main (main=0x558b7a13d7f0, argc=5, argv=0x7fff48fe7158, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff48fe7148) at ../csu/libc-start.c:291
#10 0x0000558b7a13d82a in _start ()

Do you have any scripts installed?

(In reply to Martin Gräßlin from comment #3)
> Do you have any scripts installed?

Not that I know of. It's a default debian installation of kwin package.

$ cat /etc/xdg/kwinscripts.knsrc
[KNewStuff3]
ProvidersUrl=http://download.kde.org/ocs/providers.xml
Categories=KWin Scripts
StandardResource=tmp
InstallationCommand=plasmapkg2 -t kwinscript -i %f
UninstallCommand=plasmapkg2 -t kwinscript -r %f

Desktop change OSD activated? It is internally implemented as a script.

(In reply to Martin Gräßlin from comment #5)
> Desktop change OSD activated? It is internally implemented as a script.

On KWin Scripts in the System Settings dialog, I have "Enforces Window Decorations...", which is enabled, MinimizeAll, Synchronize Skip Switcher..., Video Wall. All 3 are disabled.

Desktop change OSD doesn't appear in this list, but it does exist in /usr/share/kwin/scripts. How can I tell if it is activated?

Ok, so there is one script which gets loaded.

(In reply to Martin Gräßlin from comment #7)
> Ok, so there is one script which gets loaded.

And... is kwin expected to crash when loading scripts?

(In reply to Orgad Shaneh from comment #8)
> (In reply to Martin Gräßlin from comment #7)
> > Ok, so there is one script which gets loaded.
> 
> And... is kwin expected to crash when loading scripts?

Obviously not.

Thank you for the report.

As it has been a while since this was reported, can you please test and confirm if this issue is still occurring or if this bug report can be marked as resolved.

I have set the bug status to "needsinfo" pending your response, please change back to "reported" or "resolved/worksforme" when you respond, thank you.

Can no longer reproduce.