Application: ksysguard (5.14.4)

Qt Version: 5.11.2
Frameworks Version: 5.52.0
Operating System: Linux 4.15.0-42-generic x86_64
Distribution: KDE neon User Edition 5.14

-- Information about the crash:
- What I was doing when the application crashed:
Tried to open ksysguard via the System Load widget in my panel to see which process was maxing out one of my CPU cores.  It gave that error each time I tried,  then the second or third time I, it crashed.  The System Monitor window did appear, but it showed nothing.  Trying to start ksysguard via the main menu had the same result.

The full text of the error dialog was:
"Sorry--System Monitor" (title)
"The file /home/myusername/.local/share/ksysguard/ProcessTable.sgrd does not contain valid XML."  (text)

The file at the location indicated had a length of 0 bytes.  I deleted it, then restarted ksysguard, and this time it showed the process table, but also another error message similar to the first, but with SystemLoad2.sgrd named.  That file was also 0 bytes, and I deleted it as well, and after that, ksysguard began to function normally once again.

The crash can be reproduced sometimes.

-- Backtrace:
Application: System Monitor (ksysguard), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f4defe92940 (LWP 1845))]

Thread 4 (Thread 0x7f4dbb1d8700 (LWP 1851)):
#0  0x00007f4def7540b4 in __GI___libc_read (fd=12, buf=0x7f4dbb1d7a9e, nbytes=10) at ../sysdeps/unix/sysv/linux/read.c:27
#1  0x00007f4dbfda4ff1 in pa_read () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-11.1.so
#2  0x00007f4dc40d99fe in pa_mainloop_prepare () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#3  0x00007f4dc40da470 in pa_mainloop_iterate () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#4  0x00007f4dc40da530 in pa_mainloop_run () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#5  0x00007f4dc40e8399 in ?? () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#6  0x00007f4dbfdd42a8 in ?? () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-11.1.so
#7  0x00007f4de3ace6db in start_thread (arg=0x7f4dbb1d8700) at pthread_create.c:463
#8  0x00007f4def76588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f4dc84f0700 (LWP 1848)):
#0  0x00007f4def758bf9 in __GI___poll (fds=0x7f4dc0004db0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f4de1b50539 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f4de1b5064c in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f4deaf2704b in QEventDispatcherGlib::processEvents (this=0x7f4dc0000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#4  0x00007f4deaecb30a in QEventLoop::exec (this=this@entry=0x7f4dc84efc30, flags=..., flags@entry=...) at kernel/qeventloop.cpp:214
#5  0x00007f4deacf6bba in QThread::exec (this=this@entry=0x7f4deb878d60 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:525
#6  0x00007f4deb600e45 in QDBusConnectionManager::run (this=0x7f4deb878d60 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#7  0x00007f4dead01adb in QThreadPrivate::start (arg=0x7f4deb878d60 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:367
#8  0x00007f4de3ace6db in start_thread (arg=0x7f4dc84f0700) at pthread_create.c:463
#9  0x00007f4def76588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f4dd7c43700 (LWP 1846)):
#0  0x00007f4de3ad49f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f4de99ec110) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x55f9e0dc04b0, cond=0x7f4de99ec0e8) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7f4de99ec0e8, mutex=0x55f9e0dc04b0) at pthread_cond_wait.c:655
#3  0x00007f4dea98079c in std::condition_variable::wait(std::unique_lock<std::mutex>&) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4  0x00007f4de8cfe217 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#5  0x00007f4de8cfe359 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#6  0x00007f4dea98657f in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7  0x00007f4de3ace6db in start_thread (arg=0x7f4dd7c43700) at pthread_create.c:463
#8  0x00007f4def76588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f4defe92940 (LWP 1845)):
[KCrash Handler]
#6  WorkSheet::refreshSheet (this=0x0) at ./gui/WorkSheet.cpp:651
#7  0x00007f4defa9eca1 in Workspace::refreshActiveWorksheet (this=<optimized out>) at ./gui/Workspace.cpp:128
#8  0x00007f4defaac2a5 in Workspace::qt_static_metacall (_o=<optimized out>, _id=<optimized out>, _a=<optimized out>, _c=QMetaObject::InvokeMetaMethod) at ./obj-x86_64-linux-gnu/gui/kdeinit_ksysguard_autogen/EWIEGA46WW/moc_Workspace.cpp:160
#9  0x00007f4defaac8ba in Workspace::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at ./obj-x86_64-linux-gnu/gui/kdeinit_ksysguard_autogen/EWIEGA46WW/moc_Workspace.cpp:137
#10 0x00007f4deaefc075 in QMetaObject::activate (sender=sender@entry=0x55f9e0f34b30, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7ffe7c25d5d0) at kernel/qobject.cpp:3771
#11 0x00007f4deaefc747 in QMetaObject::activate (sender=sender@entry=0x55f9e0f34b30, m=m@entry=0x7f4dec846840 <QAction::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7ffe7c25d5d0) at kernel/qobject.cpp:3633
#12 0x00007f4dec1756b2 in QAction::triggered (this=this@entry=0x55f9e0f34b30, _t1=<optimized out>) at .moc/moc_qaction.cpp:376
#13 0x00007f4dec177cec in QAction::activate (this=0x55f9e0f34b30, event=<optimized out>) at kernel/qaction.cpp:1166
#14 0x00007f4dec2eb3bc in QMenuPrivate::activateCausedStack (this=this@entry=0x55f9e0f69820, causedStack=..., action=action@entry=0x55f9e0f34b30, action_e=action_e@entry=QAction::Trigger, self=self@entry=true) at widgets/qmenu.cpp:1371
#15 0x00007f4dec2f293b in QMenuPrivate::activateAction (this=this@entry=0x55f9e0f69820, action=action@entry=0x55f9e0f34b30, action_e=action_e@entry=QAction::Trigger, self=self@entry=true) at widgets/qmenu.cpp:1448
#16 0x00007f4dec2f37f3 in QMenu::mouseReleaseEvent (this=<optimized out>, e=0x7ffe7c25dbf0) at widgets/qmenu.cpp:2942
#17 0x00007f4dec1baa98 in QWidget::event (this=this@entry=0x55f9e0fb9e40, event=event@entry=0x7ffe7c25dbf0) at kernel/qwidget.cpp:9287
#18 0x00007f4dec2f5b2b in QMenu::event (this=0x55f9e0fb9e40, e=0x7ffe7c25dbf0) at widgets/qmenu.cpp:3064
#19 0x00007f4dec17be1c in QApplicationPrivate::notify_helper (this=this@entry=0x55f9e0da8680, receiver=receiver@entry=0x55f9e0fb9e40, e=e@entry=0x7ffe7c25dbf0) at kernel/qapplication.cpp:3727
#20 0x00007f4dec183f87 in QApplication::notify (this=<optimized out>, receiver=0x55f9e0fb9e40, e=0x7ffe7c25dbf0) at kernel/qapplication.cpp:3203
#21 0x00007f4deaeccfe8 in QCoreApplication::notifyInternal2 (receiver=receiver@entry=0x55f9e0fb9e40, event=event@entry=0x7ffe7c25dbf0) at kernel/qcoreapplication.cpp:1048
#22 0x00007f4dec1828d2 in QCoreApplication::sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#23 QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x55f9e0fb9e40, event=event@entry=0x7ffe7c25dbf0, alienWidget=0x0, alienWidget@entry=0x55f9e0fb9e40, nativeWidget=0x55f9e0fb9e40, buttonDown=buttonDown@entry=0x7f4dec875850 <qt_button_down>, lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:2695
#24 0x00007f4dec1d594a in QWidgetWindow::handleMouseEvent (this=this@entry=0x7f4dcc00d9b0, event=event@entry=0x7ffe7c25dff0) at kernel/qwidgetwindow.cpp:555
#25 0x00007f4dec1d8229 in QWidgetWindow::event (this=0x7f4dcc00d9b0, event=0x7ffe7c25dff0) at kernel/qwidgetwindow.cpp:280
#26 0x00007f4dec17be1c in QApplicationPrivate::notify_helper (this=this@entry=0x55f9e0da8680, receiver=receiver@entry=0x7f4dcc00d9b0, e=e@entry=0x7ffe7c25dff0) at kernel/qapplication.cpp:3727
#27 0x00007f4dec1833ef in QApplication::notify (this=0x7ffe7c25e330, receiver=0x7f4dcc00d9b0, e=0x7ffe7c25dff0) at kernel/qapplication.cpp:3486
#28 0x00007f4deaeccfe8 in QCoreApplication::notifyInternal2 (receiver=receiver@entry=0x7f4dcc00d9b0, event=event@entry=0x7ffe7c25dff0) at kernel/qcoreapplication.cpp:1048
#29 0x00007f4deb97f7bb in QCoreApplication::sendSpontaneousEvent (event=0x7ffe7c25dff0, receiver=0x7f4dcc00d9b0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:237
#30 QGuiApplicationPrivate::processMouseEvent (e=0x55f9e0fb92a0) at kernel/qguiapplication.cpp:2082
#31 0x00007f4deb981335 in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x55f9e0fb92a0) at kernel/qguiapplication.cpp:1817
#32 0x00007f4deb959f5b in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:1032
#33 0x00007f4dd6a8376b in QPAEventDispatcherGlib::processEvents (this=0x55f9e0e2e8c0, flags=...) at qeventdispatcher_glib.cpp:70
#34 0x00007f4deaecb30a in QEventLoop::exec (this=this@entry=0x7ffe7c25e260, flags=..., flags@entry=...) at kernel/qeventloop.cpp:214
#35 0x00007f4deaed44d0 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1336
#36 0x00007f4deb9759cc in QGuiApplication::exec () at kernel/qguiapplication.cpp:1762
#37 0x00007f4dec17bd75 in QApplication::exec () at kernel/qapplication.cpp:2901
#38 0x00007f4defaa99db in kdemain (argc=<optimized out>, argv=<optimized out>) at ./gui/ksysguard.cpp:609
#39 0x00007f4def665b97 in __libc_start_main (main=0x55f9dfdde720 <main>, argc=1, argv=0x7ffe7c25e478, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe7c25e468) at ../csu/libc-start.c:310
#40 0x000055f9dfdde75a in _start ()

Reported using DrKonqi