Bug 422987

Summary: Sometimes Discover crashes at startup on Wayland when I open a .flatpakref file while cpu is being fullly used
Product: [Applications] Discover Reporter: Patrick Silva <bugseforuns>
Component: discoverAssignee: Dan Leinir Turthra Jensen <leinir>
Status: RESOLVED UPSTREAM    
Severity: crash CC: aleixpol
Priority: NOR Keywords: drkonqi
Version: 5.19.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Patrick Silva 2020-06-14 20:22:38 UTC 
Application: plasma-discover (5.19.0)

Qt Version: 5.15.0
Frameworks Version: 5.71.0
Operating System: Linux 5.6.15-arch1-1 x86_64
Windowing system: Wayland
Distribution: Arch Linux

-- Information about the crash:
- What I was doing when the application crashed:
I was building source code, I tried to open a .flatpakref file with Discover, Discover froze (window decoration said "Not responding...") and then crashed a few seconds later.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Discover (plasma-discover), signal: Aborted

[KCrash Handler]
#4  0x00007f468156b355 in raise () at /usr/lib/libc.so.6
#5  0x00007f4681554853 in abort () at /usr/lib/libc.so.6
#6  0x00007f46819689ac in qt_message_fatal (message=<synthetic pointer>..., context=...) at global/qlogging.cpp:1914
#7  QMessageLogger::fatal(char const*, ...) const (this=this@entry=0x7f4641737aa0, msg=msg@entry=0x7f467cd980b8 "The Wayland connection broke. Did the Wayland compositor die?") at global/qlogging.cpp:893
#8  0x00007f467cd110fa in QtWaylandClient::QWaylandDisplay::checkError() const (this=<optimized out>) at /usr/include/qt/QtCore/qlogging.h:90
#9  QtWaylandClient::QWaylandDisplay::checkError() const (this=<optimized out>) at /usr/src/debug/qtwayland-everywhere-src-5.15.0/src/client/qwaylanddisplay.cpp:204
#10 0x00007f467cd1f699 in QtWaylandClient::QWaylandDisplay::dispatchQueueWhile(wl_event_queue*, std::function<bool ()>, int) (this=0x556e0ce48bd0, queue=0x556e0d4e2fb0, condition=..., timeout=timeout@entry=100) at /usr/src/debug/qtwayland-everywhere-src-5.15.0/src/client/qwaylanddisplay.cpp:260
#11 0x00007f467cd24723 in QtWaylandClient::QWaylandWindow::waitForFrameSync(int) (this=0x556e0d8d2730, timeout=100) at /usr/include/c++/10.1.0/new:175
#12 0x00007f467976b6cc in QtWaylandClient::QWaylandGLContext::swapBuffers(QPlatformSurface*) (this=0x556e10d27260, surface=<optimized out>) at /usr/src/debug/qtwayland-everywhere-src-5.15.0/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp:486
#13 0x00007f46835e9c0d in QSGRenderThread::syncAndRender(QImage*) (this=0x556e10d26fe0, grabImage=0x0) at /usr/src/debug/qtdeclarative-everywhere-src-5.15.0/src/quick/scenegraph/qsgthreadedrenderloop.cpp:870
#14 0x00007f46835ea3d7 in QSGRenderThread::run() (this=0x556e10d26fe0) at /usr/src/debug/qtdeclarative-everywhere-src-5.15.0/src/quick/scenegraph/qsgthreadedrenderloop.cpp:1043
#15 0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e10d26fe0) at thread/qthread_unix.cpp:342
#16 0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#17 0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f46819abce8 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x556e0dc73360) at thread/qwaitcondition_unix.cpp:136
#2  QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x556e0dc73360) at thread/qwaitcondition_unix.cpp:144
#3  QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x556e0dc732d0, mutex=mutex@entry=0x556e0da735b8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007f46819a9fd4 in QThreadPoolThread::run() (this=0x556e0dc732c0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e0dc732c0) at thread/qthread_unix.cpp:342
#6  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e560f38 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007f465c12322e in _ostree_fetcher_mirrored_request_to_membuf_once (error=0x7f46427399a8, cancellable=0x0, max_size=10485760, out_contents=0x7f4642739ac8, flags=OSTREE_FETCHER_REQUEST_OPTIONAL_CONTENT, filename=0x7f465c1356bd "summary.sig", mirrorlist=0x7f463cf323a0, fetcher=0x7f465402d440) at src/libostree/ostree-fetcher-util.c:86
#4  _ostree_fetcher_mirrored_request_to_membuf (fetcher=0x7f465402d440, mirrorlist=0x7f463cf323a0, filename=0x7f465c1356bd "summary.sig", flags=flags@entry=OSTREE_FETCHER_REQUEST_OPTIONAL_CONTENT, n_network_retries=<optimized out>, out_contents=0x7f4642739ac8, max_size=10485760, cancellable=0x0, error=0x7f4642739ba8) at src/libostree/ostree-fetcher-util.c:128
#5  0x00007f465c0e4670 in _ostree_preload_metadata_file (fetcher=fetcher@entry=0x7f465402d440, mirrorlist=<optimized out>, filename=filename@entry=0x7f465c1356bd "summary.sig", is_metalink=is_metalink@entry=0, n_network_retries=<optimized out>, out_bytes=out_bytes@entry=0x7f4642739ac8, cancellable=0x0, error=0x7f4642739ba8, self=0x556e0db7d060) at src/libostree/ostree-repo-pull.c:3120
#6  0x00007f465c0ef45a in repo_remote_fetch_summary (error=0x7f4642739ba8, cancellable=0x0, out_from_cache=<synthetic pointer>, out_signatures=0x7f4642739ac8, out_summary=0x7f4642739ac0, options=0x0, metalink_url_string=0x0, name=0x556e0d4248e0 "gnome-nightly", self=0x556e0db7d060) at src/libostree/ostree-repo-pull.c:3291
#7  ostree_repo_remote_fetch_summary_with_options (self=0x556e0db7d060, name=name@entry=0x556e0d4248e0 "gnome-nightly", options=options@entry=0x0, out_summary=out_summary@entry=0x7f4642739bb8, out_signatures=out_signatures@entry=0x7f4642739bc0, cancellable=cancellable@entry=0x0, error=0x7f4642739ba8) at src/libostree/ostree-repo-pull.c:6178
#8  0x00007f465c0cdd87 in ostree_repo_remote_fetch_summary (self=<optimized out>, name=name@entry=0x556e0d4248e0 "gnome-nightly", out_summary=out_summary@entry=0x7f4642739bb8, out_signatures=out_signatures@entry=0x7f4642739bc0, cancellable=cancellable@entry=0x0, error=error@entry=0x7f4642739ba8) at src/libostree/ostree-repo.c:2389
#9  0x00007f465c209799 in flatpak_dir_remote_fetch_summary (error=0x7f4642739ba8, cancellable=0x0, out_summary_sig=<synthetic pointer>, out_summary=<synthetic pointer>, only_cached=0, name_or_uri=0x556e0d4248e0 "gnome-nightly", self=0x556e1023e680) at common/flatpak-dir.c:10637
#10 _flatpak_dir_get_remote_state (self=self@entry=0x556e1023e680, remote_or_uri=remote_or_uri@entry=0x556e0d4248e0 "gnome-nightly", optional=optional@entry=1, local_only=local_only@entry=0, only_cached=only_cached@entry=0, opt_summary=opt_summary@entry=0x0, opt_summary_sig=0x0, cancellable=0x0, error=0x7f4642739c80) at common/flatpak-dir.c:10729
#11 0x00007f465c209a5b in flatpak_dir_get_remote_state_optional (self=self@entry=0x556e1023e680, remote=remote@entry=0x556e0d4248e0 "gnome-nightly", only_cached=only_cached@entry=0, cancellable=cancellable@entry=0x0, error=error@entry=0x7f4642739c80) at common/flatpak-dir.c:10808
#12 0x00007f465c216b8e in flatpak_installation_list_installed_refs_for_update (self=<optimized out>, cancellable=0x556e0d98c1a0, error=error@entry=0x7f4642739cd0) at common/flatpak-installation.c:1055
#13 0x00007f465c3b45c7 in operator() (__closure=0x556e121d9fb8) at /usr/src/debug/discover-5.19.0/libdiscover/backends/FlatpakBackend/FlatpakBackend.cpp:815
#15 QtConcurrent::RunFunctionTask<_GPtrArray*>::run() (this=0x556e121d9f90) at /usr/include/qt/QtConcurrent/qtconcurrentrunbase.h:108
#16 0x00007f46819a9de2 in QThreadPoolThread::run() (this=0x556e0db87a20) at thread/qthreadpool.cpp:99
#17 0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e0db87a20) at thread/qthread_unix.cpp:342
#18 0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#19 0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f46819a80c2 in QtLinuxFutex::_q_futex(int*, int, int, unsigned long long, int*, int) (val3=0, addr2=0x0, val2=0, val=<optimized out>, op=0, addr=<optimized out>) at thread/qfutex_p.h:133
#2  QtLinuxFutex::futexWait<QBasicAtomicInteger<unsigned int> >(QBasicAtomicInteger<unsigned int>&, QBasicAtomicInteger<unsigned int>::Type) (expectedValue=<optimized out>, futex=...) at thread/qfutex_p.h:135
#3  futexSemaphoreTryAcquire_loop<false>(QBasicAtomicInteger<unsigned long long>&, unsigned long long, unsigned long long, int) (timeout=-1, nn=8589934593, curValue=<optimized out>, u=...) at thread/qsemaphore.cpp:219
#4  futexSemaphoreTryAcquire<false>(QBasicAtomicInteger<unsigned long long>&, int, int) (timeout=-1, n=n@entry=1, u=..., u@entry=<error reading variable: Cannot access memory at address 0x1ffffff41>) at thread/qsemaphore.cpp:262
#5  QSemaphore::acquire(int) (this=this@entry=0x7f4643ffd560, n=n@entry=1) at thread/qsemaphore.cpp:326
#6  0x00007f4681bc1867 in doActivate<false>(QObject*, int, void**) (sender=0x556e0da0db00, signal_index=5, argv=0x7f4643ffd580) at /usr/include/c++/10.1.0/bits/atomic_base.h:776
#7  0x00007f4681bc1940 in doActivate<false>(QObject*, int, void**) (sender=0x7f4638004e20, signal_index=3, argv=0x7f4643ffd660, argv@entry=0x0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:395
#8  0x00007f4681bbaaa0 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=<optimized out>, m=m@entry=0x7f46811b2200 <QHttpNetworkReply::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3946
#9  0x00007f4681154891 in QHttpNetworkReply::encrypted() (this=<optimized out>) at .moc/moc_qhttpnetworkreply_p.cpp:343
#10 0x00007f46810cd009 in QHttpNetworkConnectionChannel::_q_encrypted() (this=0x7f4638004168) at access/qhttpnetworkconnectionchannel.cpp:1288
#11 0x00007f4681bc1940 in doActivate<false>(QObject*, int, void**) (sender=0x7f4638007470, signal_index=16, argv=0x7f4643ffd7b0, argv@entry=0x0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:395
#12 0x00007f4681bbaaa0 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x7f4638007470, m=m@entry=0x7f46811b1140 <QSslSocket::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3946
#13 0x00007f4681130e31 in QSslSocket::encrypted() (this=this@entry=0x7f4638007470) at .moc/moc_qsslsocket.cpp:317
#14 0x00007f4681142566 in QSslSocketBackendPrivate::continueHandshake() (this=0x7f46380080c0) at ssl/qsslsocket_openssl.cpp:1938
#15 0x00007f4681148261 in QSslSocketBackendPrivate::startHandshake() (this=this@entry=0x7f46380080c0) at ssl/qsslsocket_openssl.cpp:1398
#16 0x00007f4681148821 in QSslSocketBackendPrivate::transmit() (this=0x7f46380080c0) at ssl/qsslsocket_openssl.cpp:1059
#17 0x00007f4681bc1940 in doActivate<false>(QObject*, int, void**) (sender=0x7f4638007920, signal_index=3, argv=0x7f4643ffea20, argv@entry=0x0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:395
#18 0x00007f4681bbaaa0 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x7f4638007920, m=m@entry=0x7f4681e1d940 <QIODevice::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3946
#19 0x00007f4681ab8a51 in QIODevice::readyRead() (this=this@entry=0x7f4638007920) at .moc/moc_qiodevice.cpp:190
#20 0x00007f468110e520 in QAbstractSocketPrivate::emitReadyRead(int) (channel=0, this=0x7f4638009520) at socket/qabstractsocket.cpp:1321
#21 QAbstractSocketPrivate::canReadNotification() (this=0x7f4638009520) at socket/qabstractsocket.cpp:748
#22 0x00007f468111e962 in QReadNotifier::event(QEvent*) (this=<optimized out>, e=<optimized out>) at socket/qnativesocketengine.cpp:1274
#23 0x00007f4682b556f2 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x7f463800c350, e=0x7f4643ffeb50) at kernel/qapplication.cpp:3671
#24 0x00007f4681b8a69a in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x7f463800c350, event=0x7f4643ffeb50) at ../../include/QtCore/5.15.0/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:325
#25 0x00007f4681be3e26 in socketNotifierSourceDispatch(GSource*, GSourceFunc, gpointer) (source=0x7f4638003bc0) at kernel/qeventdispatcher_glib.cpp:107
#26 0x00007f467e51343c in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#27 0x00007f467e560fa9 in  () at /usr/lib/libglib-2.0.so.0
#28 0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#29 0x00007f4681be3211 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f4638000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#30 0x00007f4681b8901c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f4643ffed60, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#31 0x00007f46819a4c32 in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#32 0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e0d9f4c50) at thread/qthread_unix.cpp:342
#33 0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#34 0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e510d6f in g_main_context_check () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e560edb in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#4  0x00007f4681be322c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f463c000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#5  0x00007f4681b8901c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f465cc0cd60, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#6  0x00007f46819a4c32 in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#7  0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e0d508140) at thread/qthread_unix.cpp:342
#8  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e510f2d in g_main_context_check () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e560edb in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007f467e511c03 in g_main_loop_run () at /usr/lib/libglib-2.0.so.0
#4  0x00007f467deca1a8 in  () at /usr/lib/libgio-2.0.so.0
#5  0x00007f467e53b511 in  () at /usr/lib/libglib-2.0.so.0
#6  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e510f2d in g_main_context_check () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e560edb in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#4  0x00007f467e512272 in  () at /usr/lib/libglib-2.0.so.0
#5  0x00007f467e53b511 in  () at /usr/lib/libglib-2.0.so.0
#6  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e560f38 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007f4681be322c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f4654000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f4681b8901c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f46715ead20, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007f46819a4c32 in QThread::exec() (this=this@entry=0x556e0d3b78e0) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007f468353918b in QQuickPixmapReader::run() (this=0x556e0d3b78e0) at /usr/src/debug/qtdeclarative-everywhere-src-5.15.0/src/quick/util/qquickpixmapcache.cpp:1008
#7  0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e0d3b78e0) at thread/qthread_unix.cpp:342
#8  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f4678ceb4cc in  () at /usr/lib/dri/i965_dri.so
#2  0x00007f4678cea7e8 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f4678ceb4cc in  () at /usr/lib/dri/i965_dri.so
#2  0x00007f4678cea7e8 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f4678ceb4cc in  () at /usr/lib/dri/i965_dri.so
#2  0x00007f4678cea7e8 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f4678ceb4cc in  () at /usr/lib/dri/i965_dri.so
#2  0x00007f4678cea7e8 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e560f38 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007f4681be322c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f466c000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f4681b8901c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f467b310d40, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007f46819a4c32 in QThread::exec() (this=this@entry=0x556e0cecf720) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007f46828a0789 in QQmlThreadPrivate::run() (this=0x556e0cecf720) at /usr/src/debug/qtdeclarative-everywhere-src-5.15.0/src/qml/qml/ftw/qqmlthread.cpp:155
#7  0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x556e0cecf720) at thread/qthread_unix.cpp:342
#8  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f467e560f38 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007f4681be322c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f4674000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f4681b8901c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f467c521d10, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007f46819a4c32 in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007f46830a5098 in QDBusConnectionManager::run() (this=0x7f4683113080 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:179
#7  0x00007f46819a5e0f in QThreadPrivate::start(void*) (arg=0x7f4683113080 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:342
#8  0x00007f4680cb7422 in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007f468162ebf3 in clone () at /usr/lib/libc.so.6

#1  0x00007f46819abd64 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x556e10d1a750) at thread/qwaitcondition_unix.cpp:146
#2  QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=<optimized out>, mutex=0x556e10d27038, deadline=...) at thread/qwaitcondition_unix.cpp:225
#3  0x00007f46835ec157 in QSGThreadedRenderLoop::polishAndSync(QSGThreadedRenderLoop::Window*, bool) (this=this@entry=0x556e0d032e20, w=w@entry=0x556e10d27140, inExpose=inExpose@entry=true) at /usr/include/qt/QtCore/qdeadlinetimer.h:68
#4  0x00007f46835ece3d in QSGThreadedRenderLoop::handleExposure(QQuickWindow*) (this=0x556e0d032e20, window=<optimized out>) at /usr/src/debug/qtdeclarative-everywhere-src-5.15.0/src/quick/scenegraph/qsgthreadedrenderloop.cpp:1373
#5  0x00007f4681f764f5 in QWindow::event(QEvent*) (this=0x556e0d1e5ce0, ev=<optimized out>) at kernel/qwindow.cpp:2433
#6  0x00007f4682b556f2 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x556e0d1e5ce0, e=0x7ffe44f721d0) at kernel/qapplication.cpp:3671
#7  0x00007f4681b8a69a in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x556e0d1e5ce0, event=0x7ffe44f721d0) at ../../include/QtCore/5.15.0/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:325
#8  0x00007f4681f6b380 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (e=0x556e121d8420) at kernel/qguiapplication.cpp:3193
#9  0x00007f4681f3f6ec in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=flags@entry=...) at kernel/qwindowsysteminterface.cpp:1175
#10 0x00007f4681f3f979 in QWindowSystemInterface::flushWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=...) at kernel/qwindowsysteminterface.cpp:1139
#11 0x00007f4681bb70b2 in QObject::event(QEvent*) (this=0x556e0d8d2730, e=0x556e13e470c0) at kernel/qobject.cpp:1314
#12 0x00007f4682b556f2 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x556e0d8d2730, e=0x556e13e470c0) at kernel/qapplication.cpp:3671
#13 0x00007f4681b8a69a in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x556e0d8d2730, event=0x556e13e470c0) at ../../include/QtCore/5.15.0/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:325
#14 0x00007f4681b8d183 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=0x0, event_type=0, data=0x556e0ce38880) at kernel/qcoreapplication.cpp:1815
#15 0x00007f4681be3bd4 in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x556e0ce82450) at kernel/qeventdispatcher_glib.cpp:277
#16 0x00007f467e51343c in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#17 0x00007f467e560fa9 in  () at /usr/lib/libglib-2.0.so.0
#18 0x00007f467e512221 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#19 0x00007f4681be3211 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x556e0ce72d90, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#20 0x00007f4681b8901c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffe44f72670, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#21 0x00007f4681b914a4 in QCoreApplication::exec() () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#22 0x0000556e0b72383f in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/discover-5.19.0/discover/main.cpp:184
[Inferior 1 (process 266748) detached]

Possible duplicates by query: bug 422614, bug 420938, bug 420828, bug 419051, bug 417285.

Reported using DrKonqi
Comment 1 Nate Graham 2021-01-13 18:44:51 UTC 
#6  QMessageLogger::fatal (this=this@entry=0x7fffd70c5ba0, msg=msg@entry=0x7ff994ac00b8 "The Wayland connection broke. Did the Wayland compositor die?") at global/qlogging.cpp:893

This means that the compositor crashed. Due to a Qt issue, when this happens, the app using it will crash too. KDE developers submitted a fix, but sadly it was not merged. See https://codereview.qt-project.org/c/qt/qtwayland/+/308984.

Until we get better handling of this in Qt, the best we can do is debug why the compositor crashed in the first place. So can you please get a backtrace of the crash in kwin_wayland and then file a new bug report with it on kwin | wayland-generic? Thanks!

You may be able to use the `coredumpctl` utility to retrieve the backtrace. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl