Application: kontact (5.9.3)

Qt Version: 5.11.3
Frameworks Version: 5.54.0
Operating System: Linux 4.19.0-2-amd64 x86_64
Distribution: Debian GNU/Linux buster/sid

-- Information about the crash:
On my system, I open Kontact and navigate to Feeds. When I secondary click on the icon and choose Quit, Kontact crashes. I can reproduce on X11 and Wayland.

The crash can be reproduced every time.

-- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fa36988df00 (LWP 1928))]

Thread 29 (Thread 0x7fa285a7f700 (LWP 12706)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa285a7e400, expected=0, futex_word=0x7fa285a7e5e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa285a7e4a0, mutex=0x7fa285a7e598, cond=0x7fa285a7e5c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa285a7e5c0, mutex=0x7fa285a7e598, abstime=0x7fa285a7e4a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 28 (Thread 0x7fa280238700 (LWP 12705)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa280237400, expected=0, futex_word=0x7fa2802375e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa2802374a0, mutex=0x7fa280237598, cond=0x7fa2802375c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa2802375c0, mutex=0x7fa280237598, abstime=0x7fa2802374a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 27 (Thread 0x7fa27a6a8700 (LWP 12703)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa27a6a7400, expected=0, futex_word=0x7fa27a6a75e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa27a6a74a0, mutex=0x7fa27a6a7598, cond=0x7fa27a6a75c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa27a6a75c0, mutex=0x7fa27a6a7598, abstime=0x7fa27a6a74a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 26 (Thread 0x7fa267cb3700 (LWP 12702)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa267cb2400, expected=0, futex_word=0x7fa267cb25e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa267cb24a0, mutex=0x7fa267cb2598, cond=0x7fa267cb25c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa267cb25c0, mutex=0x7fa267cb2598, abstime=0x7fa267cb24a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 25 (Thread 0x7fa35c83a700 (LWP 10249)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa35c839400, expected=0, futex_word=0x7fa35c8395e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa35c8394a0, mutex=0x7fa35c839598, cond=0x7fa35c8395c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa35c8395c0, mutex=0x7fa35c839598, abstime=0x7fa35c8394a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 24 (Thread 0x7fa28272a700 (LWP 2001)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa282729400, expected=0, futex_word=0x7fa2827295e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa2827294a0, mutex=0x7fa282729598, cond=0x7fa2827295c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa2827295c0, mutex=0x7fa282729598, abstime=0x7fa2827294a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 23 (Thread 0x7fa2873e7700 (LWP 1970)):
#0  g_main_context_check (context=context@entry=0x7fa34c0054e0, max_priority=2147483647, fds=fds@entry=0x7fa34c009740, n_fds=n_fds@entry=1) at ../../../glib/gmain.c:3747
#1  0x00007fa37d0e60e0 in g_main_context_iterate (context=context@entry=0x7fa34c0054e0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:3917
#2  0x00007fa37d0e625c in g_main_context_iteration (context=0x7fa34c0054e0, may_block=may_block@entry=1) at ../../../glib/gmain.c:3981
#3  0x00007fa37f34b04b in QEventDispatcherGlib::processEvents (this=0x7fa34c005410, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#4  0x00007fa37f2f814b in QEventLoop::exec (this=this@entry=0x7fa2873e66a0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#5  0x00007fa37f1470d6 in QThread::exec (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#6  0x00007fa37f150c77 in QThreadPrivate::start (arg=0x55f176af7870) at thread/qthread_unix.cpp:367
#7  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8  0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 22 (Thread 0x7fa31dee5700 (LWP 1957)):
#0  _IO_new_file_xsputn (f=0x7fa37eee9680 <_IO_2_1_stderr_>, data=0x7fa31dee18f0, n=39) at fileops.c:1211
#1  0x00007fa37ed7fb32 in buffered_vfprintf (s=s@entry=0x7fa37eee9680 <_IO_2_1_stderr_>, format=format@entry=0x7fa372f70848 "[%s] %s\n", args=args@entry=0x7fa31dee3eb0) at ../libio/libioP.h:839
#2  0x00007fa37ed7d0b2 in _IO_vfprintf_internal (s=s@entry=0x7fa37eee9680 <_IO_2_1_stderr_>, format=format@entry=0x7fa372f70848 "[%s] %s\n", ap=ap@entry=0x7fa31dee3eb0) at vfprintf.c:1296
#3  0x00007fa37ee35866 in ___fprintf_chk (fp=0x7fa37eee9680 <_IO_2_1_stderr_>, flag=flag@entry=1, format=format@entry=0x7fa372f70848 "[%s] %s\n") at fprintf_chk.c:35
#4  0x00007fa372f58a5a in fprintf (__fmt=0x7fa372f70848 "[%s] %s\n", __stream=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/stdio2.h:97
#5  event_log (msg=0x7fa31dee3fa0 "epoll_wait: Bad file descriptor", severity=2) at log.c:251
#6  event_logv_ (severity=severity@entry=2, errstr=0x7fa37eeae809 "Bad file descriptor", fmt=fmt@entry=0x7fa372f709b9 "epoll_wait", ap=ap@entry=0x7fa31dee43d0) at log.c:216
#7  0x00007fa372f58c34 in event_warn (fmt=fmt@entry=0x7fa372f709b9 "epoll_wait") at log.c:127
#8  0x00007fa372f5a588 in epoll_dispatch (base=0x7fa3500031b0, tv=<optimized out>) at epoll.c:468
#9  0x00007fa372f50329 in event_base_loop (base=0x7fa3500031b0, flags=<optimized out>) at event.c:1947
#10 0x00007fa3777d5779 in base::MessagePumpLibevent::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#11 0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#12 0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#13 0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#14 0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#15 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 21 (Thread 0x7fa31effd700 (LWP 1955)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa3736bbfb8 <QTWTF::pageheap_memory+57592>) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa3736bbf68 <QTWTF::pageheap_memory+57512>, cond=0x7fa3736bbf90 <QTWTF::pageheap_memory+57552>) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa3736bbf90 <QTWTF::pageheap_memory+57552>, mutex=0x7fa3736bbf68 <QTWTF::pageheap_memory+57512>) at pthread_cond_wait.c:655
#3  0x00007fa3735c4e4a in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7fa3736adec0 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#4  0x00007fa3735c4e69 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#5  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 20 (Thread 0x7fa31f7fe700 (LWP 1954)):
#0  __libc_enable_asynccancel () at ../sysdeps/unix/sysv/linux/x86_64/cancellation.S:56
#1  0x00007fa37ee1bb36 in __GI___poll (fds=fds@entry=0x7fa340008420, nfds=nfds@entry=3, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#2  0x00007fa368a79101 in poll (__timeout=-1, __nfds=3, __fds=0x7fa340008420) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#3  poll_func (ufds=0x7fa340008420, nfds=3, timeout=-1, userdata=0x55f17673e1c0) at pulse/thread-mainloop.c:69
#4  0x00007fa368a6a920 in pa_mainloop_poll (m=m@entry=0x55f1767418d0) at pulse/mainloop.c:824
#5  0x00007fa368a6af6e in pa_mainloop_iterate (m=0x55f1767418d0, block=<optimized out>, retval=0x0) at pulse/mainloop.c:926
#6  0x00007fa368a6b020 in pa_mainloop_run (m=0x55f1767418d0, retval=retval@entry=0x0) at pulse/mainloop.c:945
#7  0x00007fa368a79049 in thread (userdata=0x55f176741890) at pulse/thread-mainloop.c:100
#8  0x00007fa368a164f8 in internal_thread_func (userdata=0x55f17675b2a0) at pulsecore/thread-posix.c:81
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 19 (Thread 0x7fa31ffff700 (LWP 1953)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa31fffe3c0, expected=0, futex_word=0x7fa31fffe5a8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa31fffe460, mutex=0x7fa31fffe558, cond=0x7fa31fffe580) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa31fffe580, mutex=0x7fa31fffe558, abstime=0x7fa31fffe460) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3777d5370 in base::MessagePumpDefault::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 18 (Thread 0x7fa324ff9700 (LWP 1952)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x55f176796c88) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x55f176796bc8, cond=0x55f176796c60) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x55f176796c60, mutex=0x55f176796bc8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa3781667d8 in cc::SingleThreadTaskGraphRunner::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa377818d86 in base::SimpleThread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8  0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 17 (Thread 0x7fa3257fa700 (LWP 1951)):
#0  0x00007fa37ee354a2 in ___vsnprintf_chk (s=s@entry=0x7fa3257f8fa0 "epoll_wait: Bad file descriptor", maxlen=maxlen@entry=1024, flags=flags@entry=1, slen=slen@entry=18446744073709551615, format=format@entry=0x7fa372f709b9 "epoll_wait", args=0x7fa3257f93d0) at vsnprintf_chk.c:31
#1  0x00007fa372f55463 in vsnprintf (__ap=<optimized out>, __fmt=0x7fa372f709b9 "epoll_wait", __n=1024, __s=0x7fa3257f8fa0 "epoll_wait: Bad file descriptor") at /usr/include/x86_64-linux-gnu/bits/stdio2.h:77
#2  evutil_vsnprintf (buf=buf@entry=0x7fa3257f8fa0 "epoll_wait: Bad file descriptor", buflen=buflen@entry=1024, format=format@entry=0x7fa372f709b9 "epoll_wait", ap=<optimized out>) at evutil.c:1853
#3  0x00007fa372f5898d in event_logv_ (severity=severity@entry=2, errstr=0x7fa37eeae809 "Bad file descriptor", fmt=fmt@entry=0x7fa372f709b9 "epoll_wait", ap=ap@entry=0x7fa3257f93d0) at log.c:205
#4  0x00007fa372f58c34 in event_warn (fmt=fmt@entry=0x7fa372f709b9 "epoll_wait") at log.c:127
#5  0x00007fa372f5a588 in epoll_dispatch (base=0x7fa338002bb0, tv=<optimized out>) at epoll.c:468
#6  0x00007fa372f50329 in event_base_loop (base=0x7fa338002bb0, flags=<optimized out>) at event.c:1947
#7  0x00007fa3777d5779 in base::MessagePumpLibevent::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#10 0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#11 0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#12 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 16 (Thread 0x7fa325ffb700 (LWP 1950)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa325ffa3c0, expected=0, futex_word=0x7fa325ffa5a8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa325ffa460, mutex=0x7fa325ffa558, cond=0x7fa325ffa580) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa325ffa580, mutex=0x7fa325ffa558, abstime=0x7fa325ffa460) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3777d5370 in base::MessagePumpDefault::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 15 (Thread 0x7fa3267fc700 (LWP 1949)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa3267fb5f8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa3267fb5a8, cond=0x7fa3267fb5d0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa3267fb5d0, mutex=0x7fa3267fb5a8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807998 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 14 (Thread 0x7fa326ffd700 (LWP 1948)):
#0  __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:63
#1  0x00007fa37ee35814 in ___fprintf_chk (fp=0x7fa37eeea8b0 <_IO_stdfile_2_lock>, flag=flag@entry=1, format=format@entry=0x7fa372f70848 "[%s] %s\n") at fprintf_chk.c:30
#2  0x00007fa372f58a5a in fprintf (__fmt=0x7fa372f70848 "[%s] %s\n", __stream=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/stdio2.h:97
#3  event_log (msg=0x7fa326ffbbd0 "epoll_wait: Bad file descriptor", severity=2) at log.c:251
#4  event_logv_ (severity=severity@entry=2, errstr=0x7fa37eeae809 "Bad file descriptor", fmt=fmt@entry=0x7fa372f709b9 "epoll_wait", ap=ap@entry=0x7fa326ffc000) at log.c:216
#5  0x00007fa372f58c34 in event_warn (fmt=fmt@entry=0x7fa372f709b9 "epoll_wait") at log.c:127
#6  0x00007fa372f5a588 in epoll_dispatch (base=0x7fa3280030d0, tv=<optimized out>) at epoll.c:468
#7  0x00007fa372f50329 in event_base_loop (base=0x7fa3280030d0, flags=<optimized out>) at event.c:1947
#8  0x00007fa3777d58b4 in base::MessagePumpLibevent::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#10 0x00007fa376905dba in content::BrowserThreadImpl::IOThreadRun(base::RunLoop*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#11 0x00007fa376906267 in content::BrowserThreadImpl::Run(base::RunLoop*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#12 0x00007fa377816338 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#13 0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#14 0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#15 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 13 (Thread 0x7fa3277fe700 (LWP 1947)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa3277fd5f8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa3277fd5a8, cond=0x7fa3277fd5d0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa3277fd5d0, mutex=0x7fa3277fd5a8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807998 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 12 (Thread 0x7fa327fff700 (LWP 1946)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa327ffe5f8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa327ffe5a8, cond=0x7fa327ffe5d0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa327ffe5d0, mutex=0x7fa327ffe5a8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807998 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 11 (Thread 0x7fa348ff9700 (LWP 1945)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa348ff85f8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa348ff85a8, cond=0x7fa348ff85d0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa348ff85d0, mutex=0x7fa348ff85a8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807998 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 10 (Thread 0x7fa3497fa700 (LWP 1944)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa3497f95f8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa3497f95a8, cond=0x7fa3497f95d0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa3497f95d0, mutex=0x7fa3497f95a8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807998 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7fa349ffb700 (LWP 1943)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa349ffa5f8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa349ffa5a8, cond=0x7fa349ffa5d0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa349ffa5d0, mutex=0x7fa349ffa5a8) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807998 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808c7f in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7fa34affd700 (LWP 1941)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa34affc400, expected=0, futex_word=0x7fa34affc5e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa34affc4a0, mutex=0x7fa34affc598, cond=0x7fa34affc5c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa34affc5c0, mutex=0x7fa34affc598, abstime=0x7fa34affc4a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7fa35d03b700 (LWP 1937)):
#0  futex_reltimed_wait_cancelable (private=0, reltime=0x7fa35d03a400, expected=0, futex_word=0x7fa35d03a5e8) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  __pthread_cond_wait_common (abstime=0x7fa35d03a4a0, mutex=0x7fa35d03a598, cond=0x7fa35d03a5c0) at pthread_cond_wait.c:533
#2  __pthread_cond_timedwait (cond=0x7fa35d03a5c0, mutex=0x7fa35d03a598, abstime=0x7fa35d03a4a0) at pthread_cond_wait.c:667
#3  0x00007fa377800a37 in base::ConditionVariable::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa37780330a in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033f2 in base::WaitableEvent::TimedWait(base::TimeDelta const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa377807981 in base::internal::SchedulerWorker::Delegate::WaitForWork(base::WaitableEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa377808e61 in base::internal::SchedulerWorker::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#10 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7fa35d83c700 (LWP 1936)):
#0  __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:63
#1  0x00007fa37ee35814 in ___fprintf_chk (fp=0x7fa37eeea8b0 <_IO_stdfile_2_lock>, flag=flag@entry=1, format=format@entry=0x7fa372f70848 "[%s] %s\n") at fprintf_chk.c:30
#2  0x00007fa372f58a5a in fprintf (__fmt=0x7fa372f70848 "[%s] %s\n", __stream=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/stdio2.h:97
#3  event_log (msg=0x7fa35d83afa0 "epoll_wait: Bad file descriptor", severity=2) at log.c:251
#4  event_logv_ (severity=severity@entry=2, errstr=0x7fa37eeae809 "Bad file descriptor", fmt=fmt@entry=0x7fa372f709b9 "epoll_wait", ap=ap@entry=0x7fa35d83b3d0) at log.c:216
#5  0x00007fa372f58c34 in event_warn (fmt=fmt@entry=0x7fa372f709b9 "epoll_wait") at log.c:127
#6  0x00007fa372f5a588 in epoll_dispatch (base=0x7fa344001d40, tv=<optimized out>) at epoll.c:468
#7  0x00007fa372f50329 in event_base_loop (base=0x7fa344001d40, flags=<optimized out>) at event.c:1947
#8  0x00007fa3777d5779 in base::MessagePumpLibevent::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#10 0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#11 0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#12 0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#13 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7fa35e03d700 (LWP 1935)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa35e03c588) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa35e03c538, cond=0x7fa35e03c560) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x7fa35e03c560, mutex=0x7fa35e03c538) at pthread_cond_wait.c:655
#3  0x00007fa377800969 in base::ConditionVariable::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#4  0x00007fa377803318 in base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#5  0x00007fa3778033af in base::WaitableEvent::Wait() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#6  0x00007fa3777d535f in base::MessagePumpDefault::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#7  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#8  0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#10 0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#11 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7fa35e83e700 (LWP 1934)):
#0  __mempcpy_ssse3 () at ../sysdeps/x86_64/multiarch/memcpy-ssse3.S:53
#1  0x00007fa37ed5ecd8 in __dcigettext (domainname=0x7fa37eeae3ba <_libc_intl_domainname> "libc", msgid1=0x7fa37eeae809 "Bad file descriptor", msgid2=msgid2@entry=0x0, plural=plural@entry=0, n=n@entry=0, category=category@entry=5) at dcigettext.c:656
#2  0x00007fa37ed5daef in __GI___dcgettext (domainname=<optimized out>, msgid=<optimized out>, category=category@entry=5) at dcgettext.c:47
#3  0x00007fa37edb516c in __GI___strerror_r (errnum=errnum@entry=9, buf=buf@entry=0x0, buflen=buflen@entry=0) at _strerror.c:71
#4  0x00007fa37edb508f in strerror (errnum=9) at strerror.c:31
#5  0x00007fa372f58c21 in event_warn (fmt=fmt@entry=0x7fa372f709b9 "epoll_wait") at log.c:127
#6  0x00007fa372f5a588 in epoll_dispatch (base=0x7fa34c001d50, tv=<optimized out>) at epoll.c:468
#7  0x00007fa372f50329 in event_base_loop (base=0x7fa34c001d50, flags=<optimized out>) at event.c:1947
#8  0x00007fa3777d57cd in base::MessagePumpLibevent::Run(base::MessagePump::Delegate*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#9  0x00007fa3777f4c8b in base::RunLoop::Run() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#10 0x00007fa377816204 in base::Thread::ThreadMain() () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#11 0x00007fa377811c81 in base::(anonymous namespace)::ThreadFunc(void*) () from /usr/lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5
#12 0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#13 0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7fa365036700 (LWP 1931)):
#0  g_main_context_query (context=context@entry=0x7fa358000bf0, max_priority=2147483647, timeout=timeout@entry=0x7fa365035524, fds=fds@entry=0x55f17b3a6780, n_fds=n_fds@entry=9) at ../../../glib/gmain.c:3625
#1  0x00007fa37d0e60b7 in g_main_context_iterate (context=context@entry=0x7fa358000bf0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:3909
#2  0x00007fa37d0e625c in g_main_context_iteration (context=0x7fa358000bf0, may_block=may_block@entry=1) at ../../../glib/gmain.c:3981
#3  0x00007fa37f34b04b in QEventDispatcherGlib::processEvents (this=0x7fa358000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#4  0x00007fa37f2f814b in QEventLoop::exec (this=this@entry=0x7fa365035670, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#5  0x00007fa37f1470d6 in QThread::exec (this=this@entry=0x7fa37e8b6d60 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#6  0x00007fa37e83c545 in QDBusConnectionManager::run (this=0x7fa37e8b6d60 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#7  0x00007fa37f150c77 in QThreadPrivate::start (arg=0x7fa37e8b6d60 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:367
#8  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#9  0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7fa366ebf700 (LWP 1930)):
#0  futex_wait_cancelable (private=0, expected=0, futex_word=0x55f176498ddc) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x55f176498d88, cond=0x55f176498db0) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x55f176498db0, mutex=0x55f176498d88) at pthread_cond_wait.c:655
#3  0x00007fa3674d0a32 in cnd_wait (mtx=0x55f176498d88, cond=0x55f176498db0) at ../src/../include/c11/threads_posix.h:155
#4  util_queue_thread_func (input=input@entry=0x55f1762bd200) at ../src/util/u_queue.c:270
#5  0x00007fa3674d05f7 in impl_thrd_routine (p=<optimized out>) at ../src/../include/c11/threads_posix.h:87
#6  0x00007fa37dc6bfa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#7  0x00007fa37ee2680f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7fa36988df00 (LWP 1928)):
[KCrash Handler]
#6  0x00007fa37eb7ac67 in Akonadi::JobPrivate::init (this=0x7fa3282604f0, parent=0x0) at ./src/core/jobs/job.cpp:103
#7  0x00007fa37eb7b212 in Akonadi::Job::Job (this=0x55f17b76ccb0, dd=0x7fa3282604f0, parent=0x0) at ./src/core/jobs/job.cpp:307
#8  0x00007fa37eb6a8ab in Akonadi::ItemFetchJob::ItemFetchJob (this=0x55f17b76ccb0, item=..., parent=0x0) at ./src/core/jobs/itemfetchjob.cpp:43
#9  0x00007fa31c39437a in KMail::MessageActions::updateActions (this=0x55f176925ce0) at ./src/messageactions.cpp:369
#10 0x00007fa31c3968a9 in KMail::MessageActions::setCurrentMessage (this=this@entry=0x55f176925ce0, msg=..., items=...) at ./src/messageactions.cpp:241
#11 0x00007fa31c378498 in KMMainWidget::updateMessageActions (this=0x55f176b22280, fast=<optimized out>) at ./src/kmmainwidget.cpp:3616
#12 0x00007fa31c37992b in KMMainWidget::initializeFilterActions (this=<optimized out>) at ./src/kmmainwidget.cpp:4211
#13 0x00007fa31c8b7eb2 in KMailPart::guiActivateEvent (this=0x55f176d7cd90, e=<optimized out>) at ./src/kmail_part.cpp:131
#14 0x00007fa37f322e0b in QObject::event (this=0x55f176d7cd90, e=<optimized out>) at kernel/qobject.cpp:1232
#15 0x00007fa37fc6f491 in QApplicationPrivate::notify_helper (this=this@entry=0x55f176228e80, receiver=receiver@entry=0x55f176d7cd90, e=e@entry=0x7fff11ab2170) at kernel/qapplication.cpp:3726
#16 0x00007fa37fc76ac0 in QApplication::notify (this=0x7fff11ab2360, receiver=0x55f176d7cd90, e=0x7fff11ab2170) at kernel/qapplication.cpp:3485
#17 0x00007fa37f2f9479 in QCoreApplication::notifyInternal2 (receiver=0x55f176d7cd90, event=event@entry=0x7fff11ab2170) at ../../include/QtCore/5.11.3/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:307
#18 0x00007fa37e6a5635 in QCoreApplication::sendEvent (event=0x7fff11ab2170, receiver=<optimized out>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qcoreapplication.h:234
#19 KParts::MainWindow::createGUI (this=0x55f1762d3990, part=0x0) at ./src/mainwindow.cpp:97
#20 0x00007fa3804b37b5 in Kontact::MainWindow::~MainWindow() () from /usr/lib/x86_64-linux-gnu/libkontactprivate.so.5
#21 0x00007fa3804b3b69 in Kontact::MainWindow::~MainWindow() () from /usr/lib/x86_64-linux-gnu/libkontactprivate.so.5
#22 0x000055f17433e77f in ?? ()
#23 0x00007fa37ed5109b in __libc_start_main (main=0x55f17433dba0, argc=1, argv=0x7fff11ab24b8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff11ab24a8) at ../csu/libc-start.c:308
#24 0x000055f17433ee4a in _start ()
[Inferior 1 (process 1928) detached]

Reported using DrKonqi