#6  0x00007f5ce645b35c in QArrayData::data (this=<optimized out>, this=<optimized out>) at /usr/include/qt5/QtCore/qarraydata.h:220
#7  QTypedArrayData<QVector2D>::data (this=<optimized out>, this=<optimized out>) at /usr/include/qt5/QtCore/qarraydata.h:208
#8  QTypedArrayData<QVector2D>::begin (this=<optimized out>, this=<optimized out>) at /usr/include/qt5/QtCore/qarraydata.h:211
#9  QVector<QVector2D>::realloc (this=0x7f5ce5c498c8, aalloc=<optimized out>, options=...) at /usr/include/qt5/QtCore/qvector.h:720
#10 0x00007f5ce644c029 in QVector<QVector2D>::append (this=this@entry=0x7f5ce5c498c8, t=...) at /usr/include/qt5/QtCore/qrefcount.h:102
#11 0x00007f5ce6453dbe in QVector<QVector2D>::operator<< (t=..., this=0x7f5ce5c498c8) at /usr/include/qt5/QtCore/qvector.h:292
#12 PieChartNode::updateTriangles (this=0x7f5cd420f1d0) at /usr/src/debug/kquickcharts-5.71.0git.20200513T193416~0be7ad0-ku.3.1.x86_64/src/scenegraph/PieChartNode.cpp:200
#13 0x00007f5ce646028b in PieChartNode::updateTriangles (this=0x7f5cd420f1d0) at /usr/include/qt5/QtCore/qvector.h:88
#14 PieChartNode::setSections (sections=..., this=0x7f5cd420f1d0) at /usr/src/debug/kquickcharts-5.71.0git.20200513T193416~0be7ad0-ku.3.1.x86_64/src/scenegraph/PieChartNode.cpp:118
#15 PieChart::updatePaintNode (this=0x558df899c510, node=0x7f5cd420f170, data=<optimized out>) at /usr/src/debug/kquickcharts-5.71.0git.20200513T193416~0be7ad0-ku.3.1.x86_64/src/PieChart.cpp:168
#16 0x00007f5d051f12e0 in QQuickWindowPrivate::updateDirtyNode (this=0x558df85bf190, item=0x558df899c510) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/items/qquickwindow.cpp:3736
#17 0x00007f5d051f1b9b in QQuickWindowPrivate::updateDirtyNodes (this=this@entry=0x558df85bf190) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/items/qquickwindow.cpp:3481
#18 0x00007f5d051f325c in QQuickWindowPrivate::syncSceneGraph (this=this@entry=0x558df85bf190) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/items/qquickwindow.cpp:448
#19 0x00007f5d05192457 in QSGRenderThread::sync (this=this@entry=0x7f5cf80079b0, inExpose=inExpose@entry=false, inGrab=inGrab@entry=false) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/scenegraph/qsgthreadedrenderloop.cpp:647
#20 0x00007f5d051943a7 in QSGRenderThread::syncAndRender (this=0x7f5cf80079b0, grabImage=0x0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/scenegraph/qsgthreadedrenderloop.cpp:778
#21 0x00007f5d05198517 in QSGRenderThread::run (this=0x7f5cf80079b0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/scenegraph/qsgthreadedrenderloop.cpp:1043
#22 0x00007f5d03415878 in QThreadPrivate::start (arg=0x7f5cf80079b0) at thread/qthread_unix.cpp:342
#23 0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#24 0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x558df8612cf8, cond=0x558df8612d20) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x558df8612d20, mutex=0x558df8612cf8) at pthread_cond_wait.c:638
#3  0x00007f5cef23e81b in cnd_wait (mtx=0x558df8612cf8, cond=0x558df8612d20) at ../include/c11/threads_posix.h:155
#4  util_queue_thread_func (input=input@entry=0x558df8640320) at ../src/util/u_queue.c:275
#5  0x00007f5cef23e697 in impl_thrd_routine (p=<optimized out>) at ../include/c11/threads_posix.h:87
#6  0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#7  0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x558df8612cf8, cond=0x558df8612d20) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x558df8612d20, mutex=0x558df8612cf8) at pthread_cond_wait.c:638
#3  0x00007f5cef23e81b in cnd_wait (mtx=0x558df8612cf8, cond=0x558df8612d20) at ../include/c11/threads_posix.h:155
#4  util_queue_thread_func (input=input@entry=0x558df8640140) at ../src/util/u_queue.c:275
#5  0x00007f5cef23e697 in impl_thrd_routine (p=<optimized out>) at ../include/c11/threads_posix.h:87
#6  0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#7  0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x558df8612cf8, cond=0x558df8612d20) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x558df8612d20, mutex=0x558df8612cf8) at pthread_cond_wait.c:638
#3  0x00007f5cef23e81b in cnd_wait (mtx=0x558df8612cf8, cond=0x558df8612d20) at ../include/c11/threads_posix.h:155
#4  util_queue_thread_func (input=input@entry=0x558df8640180) at ../src/util/u_queue.c:275
#5  0x00007f5cef23e697 in impl_thrd_routine (p=<optimized out>) at ../include/c11/threads_posix.h:87
#6  0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#7  0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x558df8612cf8, cond=0x558df8612d20) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x558df8612d20, mutex=0x558df8612cf8) at pthread_cond_wait.c:638
#3  0x00007f5cef23e81b in cnd_wait (mtx=0x558df8612cf8, cond=0x558df8612d20) at ../include/c11/threads_posix.h:155
#4  util_queue_thread_func (input=input@entry=0x558df86401a0) at ../src/util/u_queue.c:275
#5  0x00007f5cef23e697 in impl_thrd_routine (p=<optimized out>) at ../include/c11/threads_posix.h:87
#6  0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#7  0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  0x00007f5d036486f1 in postEventSourcePrepare (timeout=0x0, s=0x7f5cf40047b0) at kernel/qeventdispatcher_glib.cpp:270
#2  postEventSourceCheck (source=0x7f5cf40047b0) at kernel/qeventdispatcher_glib.cpp:270
#3  0x00007f5d01a5f449 in g_main_context_check () from /usr/lib64/libglib-2.0.so.0
#4  0x00007f5d01a5f982 in ?? () from /usr/lib64/libglib-2.0.so.0
#5  0x00007f5d01a5faff in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#6  0x00007f5d0364802b in QEventDispatcherGlib::processEvents (this=0x7f5cf4000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#7  0x00007f5d035ee2eb in QEventLoop::exec (this=this@entry=0x7f5cfcffbd80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#8  0x00007f5d0341479e in QThread::exec (this=this@entry=0x558df8314b10) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#9  0x00007f5d04e1a0e5 in QQmlThreadPrivate::run (this=0x558df8314b10) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/qml/qml/ftw/qqmlthread.cpp:155
#10 0x00007f5d03415878 in QThreadPrivate::start (arg=0x558df8314b10) at thread/qthread_unix.cpp:342
#11 0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#12 0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  0x00007f5d01a5f9de in ?? () from /usr/lib64/libglib-2.0.so.0
#2  0x00007f5d01a5faff in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007f5d0364802b in QEventDispatcherGlib::processEvents (this=0x7f5cf0000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f5d035ee2eb in QEventLoop::exec (this=this@entry=0x7f5cfe31fd70, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007f5d0341479e in QThread::exec (this=this@entry=0x7f5d047f3d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007f5d047724f7 in QDBusConnectionManager::run (this=0x7f5d047f3d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:179
#7  0x00007f5d03415878 in QThreadPrivate::start (arg=0x7f5d047f3d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:342
#8  0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  0x00007f5d055c7772 in poll (__timeout=-1, __nfds=1, __fds=0x7f5cfee89ca8) at /usr/include/bits/poll2.h:46
#2  _xcb_conn_wait (cond=<optimized out>, count=<optimized out>, vector=<optimized out>, c=<optimized out>) at xcb_conn.c:480
#3  _xcb_conn_wait (c=0x558df800ebf0, cond=<optimized out>, vector=0x0, count=0x0) at xcb_conn.c:436
#4  0x00007f5d055c843a in xcb_wait_for_event (c=c@entry=0x558df800ebf0) at xcb_in.c:697
#5  0x00007f5cff054170 in QXcbEventQueue::run (this=0x558df8002a60) at qxcbeventqueue.cpp:228
#6  0x00007f5d03415878 in QThreadPrivate::start (arg=0x558df8002a60) at thread/qthread_unix.cpp:342
#7  0x00007f5d02761efa in start_thread (arg=<optimized out>) at pthread_create.c:477
#8  0x00007f5d0309e3bf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x558df8a20870, cond=0x558df8a20898) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x558df8a20898, mutex=0x558df8a20870) at pthread_cond_wait.c:638
#3  0x00007f5d0341b5eb in QWaitConditionPrivate::wait (deadline=..., this=0x558df8a20870) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x7f5cf8007a08, deadline=...) at thread/qwaitcondition_unix.cpp:225
#5  0x00007f5d05196737 in QSGThreadedRenderLoop::polishAndSync (this=this@entry=0x558df8830f00, w=0x558df8091630, inExpose=inExpose@entry=false) at /usr/include/qt5/QtCore/qdeadlinetimer.h:68
#6  0x00007f5d0519730c in QSGThreadedRenderLoop::handleUpdateRequest (this=0x558df8830f00, window=0x558df80d7360) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/scenegraph/qsgthreadedrenderloop.cpp:1428
#7  0x00007f5d052005d5 in QQuickWindow::event (this=0x558df80d7360, e=0x7ffe8654f5c0) at /usr/src/debug/libqt5-qtdeclarative-5.15.0~rc-ku.1.1.x86_64/src/quick/items/qquickwindow.cpp:1757
#8  0x0000558df6932604 in ?? ()
#9  0x00007f5d04194cdf in QApplicationPrivate::notify_helper (this=this@entry=0x558df7ff8c30, receiver=receiver@entry=0x558df80d7360, e=e@entry=0x7ffe8654f5c0) at kernel/qapplication.cpp:3671
#10 0x00007f5d0419db60 in QApplication::notify (this=0x7ffe8654fc60, receiver=0x558df80d7360, e=0x7ffe8654f5c0) at kernel/qapplication.cpp:3417
#11 0x00007f5d035ef6fa in QCoreApplication::notifyInternal2 (receiver=0x558df80d7360, event=0x7ffe8654f5c0) at ../../include/QtCore/5.15.0/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:325
#12 0x00007f5d03a1b914 in QPlatformWindow::deliverUpdateRequest (this=<optimized out>) at kernel/qplatformwindow.cpp:789
#13 QPlatformWindow::windowEvent (this=<optimized out>, event=<optimized out>) at kernel/qplatformwindow.cpp:476
#14 0x00007f5d0419d8db in QApplication::notify (this=0x7ffe8654fc60, receiver=0x558df80d7360, e=0x7ffe8654f850) at kernel/qapplication.cpp:2861
#15 0x00007f5d035ef6fa in QCoreApplication::notifyInternal2 (receiver=0x558df80d7360, event=0x7ffe8654f850) at ../../include/QtCore/5.15.0/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:325
#16 0x00007f5d036473e0 in QTimerInfoList::activateTimers (this=0x558df80c32e0) at kernel/qtimerinfo_unix.cpp:643
#17 0x00007f5d03647c64 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:183
#18 0x00007f5d01a5f6e8 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#19 0x00007f5d01a5fa70 in ?? () from /usr/lib64/libglib-2.0.so.0
#20 0x00007f5d01a5faff in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#21 0x00007f5d0364800e in QEventDispatcherGlib::processEvents (this=0x558df80c3220, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#22 0x00007f5d035ee2eb in QEventLoop::exec (this=this@entry=0x7ffe8654fa90, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#23 0x00007f5d035f6200 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#24 0x0000558df6901c9c in ?? ()
#25 0x00007f5d02fc5ceb in __libc_start_main (main=0x558df68ff8e0, argc=1, argv=0x7ffe8654fe28, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe8654fe18) at ../csu/libc-start.c:308
#26 0x0000558df69027ba in _start ()
[Inferior 1 (process 16830) detached]

With the recent fixes and the fact I couldn't reproduce it, I think it is better to close it.