Bug 476043

As the message at the top of the SUMMARY says, 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)
> As the message at the top of the SUMMARY says, 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!

I know. I was about to do that... but weirdly enough, the crashes I experienced for months, were resolved after disabling the tooltips.

I reenabled the tooltips with the intention to attach the backtrace to this bug but, hey, plasma isn't crashing anymore. I know it sounds weird but it's how it happened.

I was waiting for the issue to reappear, then I saw your response. It the issue comes back, I will attach the backtrace. In the meantime please just ignore.

Happened again. It may be starting to happen after waking up from suspend rather than other things. It my be unrelated to bug id=357895

Created attachment 162553 [details]
backtrace

Thanks. Pasting the backtrace inline for searchability:

Thread 1 (Thread 0x7fd1f8e20e80 (LWP 188992)):
[KCrash Handler]
#4  0x00007fd1fd483245 in QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> >::operator->() const (this=0x4d9) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qscopedpointer.h:118
#5  qGetPtrHelper<QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> > const>(QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> > const&) (ptr=...) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qglobal.h:1151
#6  QQuickWindow::d_func() const (this=0x4d1) at items/qquickwindow.h:79
#7  QQuickWindow::mouseGrabberItem() const (this=0x4d1) at items/qquickwindow.cpp:1740
#8  0x00007fd1fd485a8f in QQuickWindowPrivate::removeGrabber(QQuickItem*, bool, bool) (this=this@entry=0x563037289ab0, grabber=grabber@entry=0x563038dd7f70, mouse=mouse@entry=true, touch=touch@entry=true) at items/qquickwindow.cpp:1007
#9  0x00007fd1fd46b575 in QQuickItemPrivate::derefWindow() (this=this@entry=0x563038eba3a0) at items/qquickitem.cpp:3035
#10 0x00007fd1fd46c164 in QQuickItem::setParentItem(QQuickItem*) (this=0x563038dd7f70, parentItem=parentItem@entry=0x0) at items/qquickitem.cpp:2717
#11 0x00007fd1fd46c464 in QQuickItem::~QQuickItem() (this=this@entry=0x563038eba230, __in_chrg=<optimized out>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:117
#12 0x00007fd1fd4d9211 in QQuickMouseArea::~QQuickMouseArea() (this=this@entry=0x563038eba230, __in_chrg=<optimized out>) at items/qquickmousearea.cpp:436
#13 0x00007fd1fd5f8969 in QQmlPrivate::QQmlElement<QQuickMouseArea>::~QQmlElement() (this=0x563038eba230, __in_chrg=<optimized out>) at ../../include/QtQml/../../src/qml/qml/qqmlprivate.h:144
#14 QQmlPrivate::QQmlElement<QQuickMouseArea>::~QQmlElement() (this=0x563038eba230, __in_chrg=<optimized out>) at ../../include/QtQml/../../src/qml/qml/qqmlprivate.h:144
#15 0x00007fd1fdde131c in PlasmaQuick::AppletQuickItem::~AppletQuickItem() () at /lib/x86_64-linux-gnu/libKF5PlasmaQuick.so.5
#16 0x00007fd1f41f34bd in AppletInterface::~AppletInterface() (this=0x563036d4d7a0, __in_chrg=<optimized out>) at ./src/scriptengines/qml/plasmoid/appletinterface.cpp:132
#17 0x00007fd1fb6e741e in QObjectPrivate::deleteChildren() (this=0x563036d4c220) at kernel/qobject.cpp:2137
#18 0x00007fd1fb6f23d6 in QObject::~QObject() (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1115
#19 0x00007fd1f41ec8cd in DeclarativeAppletScript::~DeclarativeAppletScript() (this=0x563036d43a90, __in_chrg=<optimized out>) at ./src/scriptengines/qml/plasmoid/declarativeappletscript.cpp:65
#20 0x00007fd1fdb246d8 in  () at /lib/x86_64-linux-gnu/libKF5Plasma.so.5
#21 0x00007fd1fdb248dd in  () at /lib/x86_64-linux-gnu/libKF5Plasma.so.5
#22 0x00007fd1fdb0e2b6 in Plasma::Applet::~Applet() () at /lib/x86_64-linux-gnu/libKF5Plasma.so.5
#23 0x00007fd1fdb0e2dd in Plasma::Applet::~Applet() () at /lib/x86_64-linux-gnu/libKF5Plasma.so.5
#24 0x00007fd1fb6e741e in QObjectPrivate::deleteChildren() (this=0x563036d366a0) at kernel/qobject.cpp:2137
#25 0x00007fd1fb6f23d6 in QObject::~QObject() (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1115
#26 0x00007fd1fdb13e0d in Plasma::Containment::~Containment() () at /lib/x86_64-linux-gnu/libKF5Plasma.so.5
#27 0x0000563035987c40 in ShellCorona::~ShellCorona() (this=0x563036824d10, __in_chrg=<optimized out>) at ./shell/shellcorona.cpp:310
#28 0x0000563035987f3d in ShellCorona::~ShellCorona() (this=0x563036824d10, __in_chrg=<optimized out>) at ./shell/shellcorona.cpp:312
#29 0x00007fd1fb6e9b83 in QObject::event(QEvent*) (this=0x563036824d10, e=0x563042ce24a0) at kernel/qobject.cpp:1334
#30 0x00007fd1fc56c763 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x563036824d10, e=0x563042ce24a0) at kernel/qapplication.cpp:3640
#31 0x00007fd1fb6bc88a in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x563036824d10, event=0x563042ce24a0) at kernel/qcoreapplication.cpp:1064
#32 0x00007fd1fb6bf987 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=0x0, event_type=52, data=0x563036522ec0) at kernel/qcoreapplication.cpp:1821
#33 0x00007fd1fb6c376c in QCoreApplication::exec() () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:86
#34 0x0000563035954a8b in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at ./shell/main.cpp:235


I can't immediately identify a cause in there.

*** Bug 476072 has been marked as a duplicate of this bug. ***

You indicated in Bug 476072 that you can reproduce the crash by running `plasmashell --replace` in a terminal window; do I have that right?

(In reply to Nate Graham from comment #7)
> You indicated in Bug 476072 that you can reproduce the crash by running
> `plasmashell --replace` in a terminal window; do I have that right?

The two bugs may have different roots:

- In 476072 the bug and backtrace are generated from executing `plasmashell --replace` in krunner.

- The bug here occurs spontaneously. The sequence is that plasmashell crashes and restarts itself. If the backtrace is equivalent to the one in 476072, does it mean that the backtrace is not really about what makes plasmashell crash, but instead about plasmashell restarting when it crashes? 

Is there a way to avoid plasmashell restarting automatically to better identify the root of what makes plasmashell fail in the first place?

The backtraces are the same, which means the same thing is ultimately causing both even if you can reproduce them in different ways (or rather, can only reproduce one, and the other is random).

Plasma always restarts with it crashes; that part isn't connected or relevant.

(In reply to Nate Graham from comment #9)
> The backtraces are the same, which means the same thing is ultimately
> causing both even if you can reproduce them in different ways (or rather,
> can only reproduce one, and the other is random).
> 
> Plasma always restarts with it crashes; that part isn't connected or
> relevant.

Ok. Do you see anything in the backtrace informative for the underlying cause? Do you think this is a plasma bug or could it be a misbehaving widget that I may have installed in my system?

Unfortunately I do not see anything that would help me debug it. A more experienced Plasma developer will be needed here.

(In reply to Nate Graham from comment #11)
> Unfortunately I do not see anything that would help me debug it. A more
> experienced Plasma developer will be needed here.

Ok thanks

Avlas, can you check again in Plasma 6.3 or later and see if this is still happening?

If so, it would also be great to learn if it's happening to you only on X11, only on Wayland, or both.

Thanks a lot!

(In reply to Nate Graham from comment #13)
> Avlas, can you check again in Plasma 6.3 or later and see if this is still
> happening?
> 
> If so, it would also be great to learn if it's happening to you only on X11,
> only on Wayland, or both.
> 
> Thanks a lot!

I have tested `plasmashell --replace` in krunner and plasma has restarted with no issues. This is my system nowadays:

Operating System: KDE neon 6.3
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.2
Kernel Version: 6.11.0-21-generic (64-bit)
Graphics Platform: Wayland

That's great news. I'll close this out for now. Feel free to re-open it if you see the same crash again. Thanks for the update.