If this is indeed reproducible, could you install debug packages for plasma-framework (libKF5Plasma) and for Kwin to create a better backtrace?

Hi there,
Thanks for taking a look.

So far I have only been using the KDE Crash reporter widget, but I think i already installed the debug symbols when I initially reported this bug.

Maybe also obligatory context: This started after one round-about update of my installed packages.

So, here is the stacktrace from this morning: (I'm not sure I can tell a difference, but it seems to contain more info.)

Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f0e87afc940 (LWP 2737))]

Thread 7 (Thread 0x7f0e73bef700 (LWP 2969)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225
#1  0x00007f0e9bdcb5f6 in QWaitConditionPrivate::wait_relative (time=30000, this=0xfd0b00) at thread/qwaitcondition_unix.cpp:126
#2  QWaitConditionPrivate::wait (time=30000, this=0xfd0b00) at thread/qwaitcondition_unix.cpp:134
#3  QWaitCondition::wait (this=this@entry=0xfc4760, mutex=mutex@entry=0xf03ad0, time=30000) at thread/qwaitcondition_unix.cpp:208
#4  0x00007f0e9bdc6e2a in QThreadPoolThread::run (this=0xfc4750) at thread/qthreadpool.cpp:127
#5  0x00007f0e9bdca808 in QThreadPrivate::start (arg=0xfc4750) at thread/qthread_unix.cpp:341
#6  0x00007f0e97e3c6ba in start_thread (arg=0x7f0e73bef700) at pthread_create.c:333
#7  0x00007f0e9e18a82d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f0e7cf79700 (LWP 2968)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f0e9b163574 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f0e9b1635b9 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f0e97e3c6ba in start_thread (arg=0x7f0e7cf79700) at pthread_create.c:333
#4  0x00007f0e9e18a82d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f0e7dfe2700 (LWP 2967)):
#0  0x00007f0e9e1809e3 in select () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f0e9bfefbcf in qt_safe_select (nfds=15, fdread=fdread@entry=0x7f0e6c000a78, fdwrite=fdwrite@entry=0x7f0e6c000d08, fdexcept=fdexcept@entry=0x7f0e6c000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f0e9bff160e in QEventDispatcherUNIX::select (timeout=0x0, exceptfds=0x7f0e6c000f98, writefds=0x7f0e6c000d08, readfds=0x7f0e6c000a78, nfds=<optimized out>, this=0x7f0e6c0008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f0e6c0008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f0e9bff1b22 in QEventDispatcherUNIX::processEvents (this=0x7f0e6c0008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f0e9bf9cffa in QEventLoop::exec (this=this@entry=0x7f0e7dfe1c60, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f0e9bdc59e4 in QThread::exec (this=this@entry=0x101d0f0) at thread/qthread.cpp:500
#7  0x00007f0e96f9e6b5 in QQmlThreadPrivate::run (this=0x101d0f0) at qml/ftw/qqmlthread.cpp:141
#8  0x00007f0e9bdca808 in QThreadPrivate::start (arg=0x101d0f0) at thread/qthread_unix.cpp:341
#9  0x00007f0e97e3c6ba in start_thread (arg=0x7f0e7dfe2700) at pthread_create.c:333
#10 0x00007f0e9e18a82d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f0e7edc2700 (LWP 2965)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225
#1  0x00007f0e9bdcb5f6 in QWaitConditionPrivate::wait_relative (time=30000, this=0xee00b0) at thread/qwaitcondition_unix.cpp:126
#2  QWaitConditionPrivate::wait (time=30000, this=0xee00b0) at thread/qwaitcondition_unix.cpp:134
#3  QWaitCondition::wait (this=this@entry=0xece010, mutex=mutex@entry=0xf03ad0, time=30000) at thread/qwaitcondition_unix.cpp:208
#4  0x00007f0e9bdc6e2a in QThreadPoolThread::run (this=0xece000) at thread/qthreadpool.cpp:127
#5  0x00007f0e9bdca808 in QThreadPrivate::start (arg=0xece000) at thread/qthread_unix.cpp:341
#6  0x00007f0e97e3c6ba in start_thread (arg=0x7f0e7edc2700) at pthread_create.c:333
#7  0x00007f0e9e18a82d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f0e84bb1700 (LWP 2741)):
#0  0x00007f0e9e1809e3 in select () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f0e9bfefbcf in qt_safe_select (nfds=8, fdread=fdread@entry=0x7f0e78000a78, fdwrite=fdwrite@entry=0x7f0e78000d08, fdexcept=fdexcept@entry=0x7f0e78000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f0e9bff160e in QEventDispatcherUNIX::select (timeout=0x0, exceptfds=0x7f0e78000f98, writefds=0x7f0e78000d08, readfds=0x7f0e78000a78, nfds=<optimized out>, this=0x7f0e780008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f0e780008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f0e9bff1b22 in QEventDispatcherUNIX::processEvents (this=0x7f0e780008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f0e9bf9cffa in QEventLoop::exec (this=this@entry=0x7f0e84bb0c50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f0e9bdc59e4 in QThread::exec (this=this@entry=0x7f0e9e813d40 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:500
#7  0x00007f0e9e7a0515 in QDBusConnectionManager::run (this=0x7f0e9e813d40 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:189
#8  0x00007f0e9bdca808 in QThreadPrivate::start (arg=0x7f0e9e813d40 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:341
#9  0x00007f0e97e3c6ba in start_thread (arg=0x7f0e84bb1700) at pthread_create.c:333
#10 0x00007f0e9e18a82d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f0e868fa700 (LWP 2740)):
#0  0x00007f0e9e17eb5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f0e9d2e4c62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f0e9d2e68d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f0e875a7d29 in QXcbEventReader::run (this=0xe17ba0) at qxcbconnection.cpp:1325
#4  0x00007f0e9bdca808 in QThreadPrivate::start (arg=0xe17ba0) at thread/qthread_unix.cpp:341
#5  0x00007f0e97e3c6ba in start_thread (arg=0x7f0e868fa700) at pthread_create.c:333
#6  0x00007f0e9e18a82d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f0e87afc940 (LWP 2737)):
[KCrash Handler]
#6  0x00007f0e9ab79e6b in ?? () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#7  0x00007f0e9ab979d1 in ?? () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#8  0x00007f0e9ab97c39 in ?? () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#9  0x00007f0e9ab8c960 in Plasma::Theme::~Theme() () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#10 0x00007f0e9ab8ca99 in Plasma::Theme::~Theme() () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#11 0x00007f0e9bfca053 in QObjectPrivate::deleteChildren (this=this@entry=0x131ac80) at kernel/qobject.cpp:1963
#12 0x00007f0e9bfd3094 in QObject::~QObject (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1034
#13 0x00007f0e9ab7c7d9 in Plasma::FrameSvg::~FrameSvg() () from /usr/lib/x86_64-linux-gnu/libKF5Plasma.so.5
#14 0x00007f0e9bfca053 in QObjectPrivate::deleteChildren (this=this@entry=0x131a430) at kernel/qobject.cpp:1963
#15 0x00007f0e9bfd3094 in QObject::~QObject (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1034
#16 0x00007f0e9748a0ed in QQuickItem::~QQuickItem (this=0x131a3a0, __in_chrg=<optimized out>) at items/qquickitem.cpp:2309
#17 0x00007f0e71f9ca06 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/core/libcorebindingsplugin.so
#18 0x00007f0e9bfca053 in QObjectPrivate::deleteChildren (this=this@entry=0x12e2710) at kernel/qobject.cpp:1963
#19 0x00007f0e9bfd3094 in QObject::~QObject (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1034
#20 0x00007f0e9748a0ed in QQuickItem::~QQuickItem (this=0x12d7120, __in_chrg=<optimized out>) at items/qquickitem.cpp:2309
#21 0x00007f0e974a41a6 in QQmlPrivate::QQmlElement<QQuickItem>::~QQmlElement (this=0x12d7120, __in_chrg=<optimized out>) at ../../include/QtQml/../../src/qml/qml/qqmlprivate.h:98
#22 QQmlPrivate::QQmlElement<QQuickItem>::~QQmlElement (this=0x12d7120, __in_chrg=<optimized out>) at ../../include/QtQml/../../src/qml/qml/qqmlprivate.h:98
#23 0x00007f0e7e338ebf in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/kwin5_aurorae.so
#24 0x00007f0e7e339009 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/kwin5_aurorae.so
#25 0x00007f0e9dc5e906 in KWin::AbstractClient::destroyDecoration() () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#26 0x00007f0e9dc6b2ec in KWin::Client::destroyDecoration() () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#27 0x00007f0e9dc622df in KWin::Client::destroyClient() () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#28 0x00007f0e9dcb2eeb in KWin::Client::unmapNotifyEvent(xcb_unmap_notify_event_t*) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#29 0x00007f0e9dcb656b in KWin::Client::windowEvent(xcb_generic_event_t*) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#30 0x00007f0e9dcb7a2a in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () from /usr/lib/x86_64-linux-gnu/libkwin.so.5
#31 0x00007f0e9bf9c16f in QAbstractEventDispatcher::filterNativeEvent (this=<optimized out>, eventType=..., message=message@entry=0x7f0e8000abb0, result=result@entry=0x7ffed568b388) at kernel/qabstracteventdispatcher.cpp:460
#32 0x00007f0e875abca5 in QXcbConnection::handleXcbEvent (this=this@entry=0xe0bd10, event=event@entry=0x7f0e8000abb0) at qxcbconnection.cpp:1091
#33 0x00007f0e875acc06 in QXcbConnection::processXcbEvents (this=0xe0bd10) at qxcbconnection.cpp:1723
#34 0x00007f0e9bfcc719 in QObject::event (this=0xe0bd10, e=<optimized out>) at kernel/qobject.cpp:1256
#35 0x00007f0e9c8d4afc in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0xe0bd10, e=0x7f0e80002240) at kernel/qapplication.cpp:3804
#36 0x00007f0e9c8da036 in QApplication::notify (this=0x7ffed568b9c0, receiver=0xe0bd10, e=0x7f0e80002240) at kernel/qapplication.cpp:3561
#37 0x00007f0e9bf9f2a8 in QCoreApplication::notifyInternal2 (receiver=0xe0bd10, event=event@entry=0x7f0e80002240) at kernel/qcoreapplication.cpp:1015
#38 0x00007f0e9bfa116a in QCoreApplication::sendEvent (event=0x7f0e80002240, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:225
#39 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0xdf3620) at kernel/qcoreapplication.cpp:1650
#40 0x00007f0e9bff1a02 in QEventDispatcherUNIX::processEvents (this=0xe46d90, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:579
#41 0x00007f0e8761b8fd in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#42 0x00007f0e9bf9cffa in QEventLoop::exec (this=this@entry=0x7ffed568b8b0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#43 0x00007f0e9bfa56bc in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1285
#44 0x00007f0e9e456226 in kdemain () from /usr/lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#45 0x00007f0e9e0a4830 in __libc_start_main (main=0x400730, argc=3, argv=0x7ffed568bb48, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffed568bb38) at ../csu/libc-start.c:291
#46 0x0000000000400769 in _start ()

Created attachment 105981 [details]
Installed packages on system for context.

I included the dpkg -l output from my system for context.

Hah.

That were not the debug symbols you were looking for it seems.

I did not find any debug packages to install, so i went ahead and followed [1] adding repositories.

Then trying to install plasma-framework-dbg (in synaptic) complains with:
plasma-framework-dbg:
  Depends: libkf5plasma5 (=5.18.0-0ubuntu1.1) but 5.34.0-0ubuntu1~ubuntu16.04~ppa1 is to be installed
  Depends: libkf5plasmaquick5 (=5.18.0-0ubuntu1.1) but 5.34.0-0ubuntu1~ubuntu16.04~ppa1 is to be installed

And this is where I'm out of my depth. :(

[1] https://wiki.ubuntu.com/Debug%20Symbol%20Packages

It looks like you are using KDE packages from backport PPAs. It is possible that those either do not offer -dbg or -dbgsym packages, or that they are hidden in extra PPAs.

I suggest to ask in an Kubuntu forum for help. You should provide the contents of /etc/apt/sources.list.d/ to make clear which PPAs you are using.

crash in plasma framework -> reassigning

Simon, any success finding matching debug packages for plasma-framework (libKF5Plasma)?

No time / success so far. Sorry.

To further investigate this issue, KDE developers need the information requested in comment #1. If you can provide it, or need help with finding that information, please add a comment.

I'm glad to say, that one of the recent package updates seems to have alleviated the issue.
I stopped to have these consistent kwin crashes on startup.

While it might be a bit sad, to not find out what went wrong here, I fear I have to suggest closing this issue.

Thanks for your time, anyway.