Bug 423040

Summary: Plasma crashes when changing chart type for memory monitor widget and reopening the settings dialogue
Product: [Plasma] plasmashell Reporter: Dan Leinir Turthra Jensen <admin>
Component: System MonitorAssignee: Marco Martin <notmart>
Status: RESOLVED FIXED    
Severity: crash CC: alexander.lohnau, nate, plasma-bugs
Priority: NOR    
Version: 5.19.0   
Target Milestone: 1.0   
Platform: openSUSE   
OS: Linux   
Latest Commit: https://invent.kde.org/plasma/libksysguard/commit/cfda69ebbd614772142abe66eaeb42d74d6f05f0 Version Fixed In: 5.20.0
Sentry Crash Report:

Description Dan Leinir Turthra Jensen 2020-06-16 09:12:55 UTC 
SUMMARY
When changing the chart type for the memory monitor in 5.19, click ok to save the setting and affect the change, you will notice the chart is just blank, and then try and show the settings dialogue again. This then crashes plasma consistently.

STEPS TO REPRODUCE
1. Add a memory monitor plasmoid to a panel
2. Right-click and pick Configure...
3. Change the chart type and click ok
4. Notice the chart is now empty
5. Attempt to configure the applet again
6. Crash

OBSERVED RESULT
* Chart goes blank
* Plasma crashes

EXPECTED RESULT
* Chart changes to the newly picked type
* Plasma doesn't crash

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.19
KDE Frameworks Version: 5.70
Qt Version: 5.15

ADDITIONAL INFORMATION
Comment 1 Alexander Lohnau 2020-06-16 10:03:55 UTC 
Same for me on KDE Neon unstable.
Comment 2 Dan Leinir Turthra Jensen 2020-06-16 10:07:10 UTC 
Here's a backtrace (with a bit of extra context) from running it through gdb:

file:///usr/share/plasma/plasmoids/org.kde.plasma.systemmonitor/contents/config/config.qml:16: TypeError: Cannot read property 'length' of undefined
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:200:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:200:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:200:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:200:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:200:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:200:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:49:5: Unable to assign [undefined] to bool
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:50:5: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:51:5: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:54:9: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:55:9: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:56:9: Unable to assign [undefined] to bool
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:49:5: Unable to assign [undefined] to bool
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:50:5: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:51:5: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:54:9: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:55:9: Unable to assign [undefined] to double
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.piechart/contents/ui/PieChart.qml:56:9: Unable to assign [undefined] to bool
file:///usr/share/ksysguard/sensorfaces/org.kde.ksysguard.linechart/contents/ui/FullRepresentation.qml:56:9: QML ExtendedLegend: Binding loop detected for property "implicitHeight"
[Thread 0x7fff9b1ef700 (LWP 29700) exited]
[New Thread 0x7fff9b1ef700 (LWP 29720)]
file:///usr/share/plasma/plasmoids/org.kde.plasma.systemmonitor/contents/config/config.qml:16: TypeError: Cannot read property 'length' of undefined
Cyclic dependency detected between "file:///usr/lib64/qt5/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml" and "file:///usr/lib64/qt5/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
file:///usr/share/plasma/plasmoids/org.kde.plasma.systemmonitor/contents/ui/config/ConfigAppearance.qml:46:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }

Thread 1 "plasmashell" received signal SIGSEGV, Segmentation fault.
QQmlData::wasDeleted (object=0x555555aa05d0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/include/QtQml/5.15.0/QtQml/private/../../../../../src/qml/qml/qqmldata_p.h:342
342     /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/include/QtQml/5.15.0/QtQml/private/../../../../../src/qml/qml/qqmldata_p.h: No such file or directory.
(gdb) thread apply all bt

Thread 20 (Thread 0x7fff9b1ef700 (LWP 29720)):
#0  0x00007ffff5827fef in poll () at /lib64/libc.so.6
#1  0x00007ffff41e15de in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ffff41e16ff in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ffff5de0f4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fff8402cc20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007ffff5d884cb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fff9b1eed80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007ffff5baa73e in QThread::exec() (this=this@entry=0x5555596206e0) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007ffff754a5d5 in QQmlThreadPrivate::run() (this=0x5555596206e0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/src/qml/qml/ftw/qqmlthread.cpp:155
#7  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x5555596206e0) at thread/qthread_unix.cpp:342
#8  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#9  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 18 (Thread 0x7fffa57af700 (LWP 29636)):
#0  0x00007ffff5827fef in poll () at /lib64/libc.so.6
#1  0x00007ffff41e15de in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ffff41e16ff in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ffff5de0f4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fff94000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007ffff5d884cb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fffa57aed60, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007ffff5baa73e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007fffa5cee428 in KCupsConnection::run() () at /usr/lib64/libkcupslib.so
#7  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x5555584b5050) at thread/qthread_unix.cpp:342
#8  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#9  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 17 (Thread 0x7fffa77fe700 (LWP 29631)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0bfc70) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0bfc70) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005680, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc005670) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc005670) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 16 (Thread 0x7fffa7fff700 (LWP 29630)):
--Type <RET> for more, q to quit, c to continue without paging--
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0bf7c0) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0bf7c0) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc0058f0, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc0058e0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc0058e0) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 15 (Thread 0x7fffc4cf1700 (LWP 29629)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0bf350) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0bf350) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005c50, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc005c40) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc005c40) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 14 (Thread 0x7fffc54f2700 (LWP 29628)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0beee0) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0beee0) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005bf0, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc005be0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc005be0) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 13 (Thread 0x7fffc5cf3700 (LWP 29627)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0bea70) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0bea70) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005ad0, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc005ac0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc005ac0) at thread/qthread_unix.cpp:342
--Type <RET> for more, q to quit, c to continue without paging--
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 12 (Thread 0x7fffc64f4700 (LWP 29626)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0be600) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0be600) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005b90, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc005b80) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc005b80) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 11 (Thread 0x7fffc6cf5700 (LWP 29625)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0be190) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0be190) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005710, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc005700) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc005700) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 10 (Thread 0x7fffd48d1700 (LWP 29624)):
#0  0x00007ffff4f55b08 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ffff5bb1554 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (deadline=..., this=0x7fffcd0bddf0) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ffff5bb1554 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., deadline=..., this=0x7fffcd0bddf0) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ffff5bb1554 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=this@entry=0x7fffcc005000, mutex=mutex@entry=0x7fffcc00aaf8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ffff5baf901 in QThreadPoolThread::run() (this=0x7fffcc004ff0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#5  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7fffcc004ff0) at thread/qthread_unix.cpp:342
#6  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#7  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 9 (Thread 0x7fffd50d4700 (LWP 29623)):
#0  0x00007ffff5827fef in poll () at /lib64/libc.so.6
#1  0x00007ffff41e15de in  () at /usr/lib64/libglib-2.0.so.0
--Type <RET> for more, q to quit, c to continue without paging--
#2  0x00007ffff41e16ff in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ffff5de0f4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fffcc000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007ffff5d884cb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fffd50d3d60, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007ffff5baa73e in QThread::exec() (this=this@entry=0x5555561bbb90) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007ffff78008d6 in QQuickPixmapReader::run() (this=0x5555561bbb90) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/src/quick/util/qquickpixmapcache.cpp:1008
#7  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x5555561bbb90) at thread/qthread_unix.cpp:342
#8  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#9  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 8 (Thread 0x7fffd77fe700 (LWP 29621)):
#0  0x00007ffff4f557e2 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007fffe9a0b08b in  () at /usr/lib64/dri/i965_dri.so
#2  0x00007fffe9a0af37 in  () at /usr/lib64/dri/i965_dri.so
#3  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#4  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 7 (Thread 0x7fffd7fff700 (LWP 29620)):
#0  0x00007ffff4f557e2 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007fffe9a0b08b in  () at /usr/lib64/dri/i965_dri.so
#2  0x00007fffe9a0af37 in  () at /usr/lib64/dri/i965_dri.so
#3  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#4  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 6 (Thread 0x7fffe8bb7700 (LWP 29619)):
#0  0x00007ffff4f557e2 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007fffe9a0b08b in  () at /usr/lib64/dri/i965_dri.so
#2  0x00007fffe9a0af37 in  () at /usr/lib64/dri/i965_dri.so
#3  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#4  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 5 (Thread 0x7fffe93b8700 (LWP 29618)):
#0  0x00007ffff4f557e2 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007fffe9a0b08b in  () at /usr/lib64/dri/i965_dri.so
#2  0x00007fffe9a0af37 in  () at /usr/lib64/dri/i965_dri.so
#3  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#4  0x00007ffff5832b1f in clone () at /lib64/libc.so.6
--Type <RET> for more, q to quit, c to continue without paging--

Thread 4 (Thread 0x7fffeb5ef700 (LWP 29600)):
#0  0x00007ffff5827fef in poll () at /lib64/libc.so.6
#1  0x00007ffff41e15de in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ffff41e16ff in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ffff5de0f4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fffe0000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007ffff5d884cb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fffeb5eed80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007ffff5baa73e in QThread::exec() (this=this@entry=0x55555593aee0) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007ffff754a5d5 in QQmlThreadPrivate::run() (this=0x55555593aee0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/src/qml/qml/ftw/qqmlthread.cpp:155
#7  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x55555593aee0) at thread/qthread_unix.cpp:342
#8  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#9  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7ffff0a42700 (LWP 29599)):
#0  0x00007ffff5827fef in poll () at /lib64/libc.so.6
#1  0x00007ffff41e15de in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ffff41e16ff in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ffff5de0f4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fffe4000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007ffff5d884cb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffff0a41d50, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007ffff5baa73e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007ffff6f05a17 in  () at /usr/lib64/libQt5DBus.so.5
#7  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x7ffff6f72d80) at thread/qthread_unix.cpp:342
#8  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#9  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7ffff1623700 (LWP 29598)):
#0  0x00007ffff5827fef in poll () at /lib64/libc.so.6
#1  0x00007ffff7cc4862 in  () at /usr/lib64/libxcb.so.1
#2  0x00007ffff7cc626c in xcb_wait_for_event () at /usr/lib64/libxcb.so.1
#3  0x00007ffff17f4f50 in  () at /usr/lib64/libQt5XcbQpa.so.5
#4  0x00007ffff5bab871 in QThreadPrivate::start(void*) (arg=0x555555628f40) at thread/qthread_unix.cpp:342
#5  0x00007ffff4f4eeaa in start_thread () at /lib64/libpthread.so.0
#6  0x00007ffff5832b1f in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7ffff36e6800 (LWP 29585)):
#0  0x00007ffff73d6325 in QQmlData::wasDeleted(QObject const*) (object=0x555555aa05d0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/include/QtQml/5.15.0/QtQml/private/../../../../../src/qml/qml/qqmldata_p.h:342
--Type <RET> for more, q to quit, c to continue without paging--
#1  0x00007ffff73d6325 in QQmlData::wasDeleted(QObject const*) (object=0x555555aa05d0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/include/QtQml/5.15.0/QtQml/private/../../../../../src/qml/qml/qqmldata_p.h:332
#2  0x00007ffff73d6325 in QV4::QObjectWrapper::getQmlProperty(QV4::ExecutionEngine*, QQmlContextData*, QObject*, QV4::String*, QV4::QObjectWrapper::RevisionMode, bool*, QQmlPropertyData**) (engine=engine@entry=0x555555892130, qmlContext=qmlContext@entry=0x555558f51110, object=0x555555aa05d0, name=0x7fffea9b05a8, revisionMode=revisionMode@entry=QV4::QObjectWrapper::CheckRevision, hasProperty=hasProperty@entry=0x7fffffffca58, property=0x7fffffffca60) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/src/qml/jsruntime/qv4qobjectwrapper.cpp:360
#3  0x00007ffff73b5d1a in QV4::QQmlContextWrapper::getPropertyAndBase(QV4::QQmlContextWrapper const*, QV4::PropertyKey, QV4::Value const*, bool*, QV4::Value*, QV4::Lookup*) (resource=<optimized out>, id=..., receiver=<optimized out>, hasProperty=0x7fffffffcad7, base=0x0, lookup=0x0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/include/QtQml/5.15.0/QtQml/private/../../../../../src/qml/common/qv4staticvalue_p.h:325
#4  0x00007ffff73b65e3 in QV4::QQmlContextWrapper::resolveQmlContextPropertyLookupGetter(QV4::Lookup*, QV4::ExecutionEngine*, QV4::Value*) (l=0x5555593b0ac0, engine=0x555555892130, base=0x0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0-1.1.x86_64/include/QtQml/5.15.0/QtQml/private/../../../../../src/qml/common/qv4staticvalue_p.h:325
#5  0x00007fff99f2dc02 in  ()
#6  0x0000000000000000 in  ()
(gdb)
Comment 3 Bug Janitor Service 2020-06-16 14:00:29 UTC 
A possibly relevant merge request was started @ https://invent.kde.org/plasma/libksysguard/-/merge_requests/27
Comment 4 Marco Martin 2020-06-16 14:15:29 UTC 
Git commit cfda69ebbd614772142abe66eaeb42d74d6f05f0 by Marco Martin.
Committed on 16/06/2020 at 14:15.
Pushed by mart into branch 'master'.

keep the same context object around

don't create/destory the translation object every time.
create it once in the ctor and keep it repurposing it for the whole
facecontroller lifecycle

M  +2    -2    faces/SensorFaceController.cpp

https://invent.kde.org/plasma/libksysguard/commit/cfda69ebbd614772142abe66eaeb42d74d6f05f0