I'm running KMail 5.4.2 on openSUSE Tumbleweed. After some time it stops working and then it crashes.

akonadi-server-16.12.2

Backtrace:

Thread 10 (Thread 0x7fdfb97fa700 (LWP 12253)):
[KCrash Handler]
#6  QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> >::data (this=0x8) at ../../src/corelib/tools/qscopedpointer.h:141
#7  qGetPtrHelper<QScopedPointer<QObjectData> > (p=...) at ../../src/corelib/global/qglobal.h:980
#8  QIODevice::d_func (this=0x0) at ../../src/corelib/io/qiodevice.h:178
#9  QIODevice::write (this=0x0, data=data@entry=0x7fdfb97f93ec "\227", maxSize=maxSize@entry=1) at io/qiodevice.cpp:1596
#10 0x00007fe044385bc0 in Akonadi::Protocol::DataStream::operator<< <unsigned char> (this=0x7fdfb97f9470, val=<optimized out>) at /usr/src/debug/akonadi-16.12.2/src/private/datastream_p_p.h:91
#11 0x00007fe04438932f in Akonadi::Protocol::CommandPrivate::serialize (stream=..., this=0x7fdf98011a00) at /usr/src/debug/akonadi-16.12.2/src/private/protocol.cpp:266
#12 Akonadi::Protocol::ResponsePrivate::serialize (stream=..., this=0x7fdf98011a00) at /usr/src/debug/akonadi-16.12.2/src/private/protocol.cpp:425
#13 Akonadi::Protocol::FetchItemsResponsePrivate::serialize (this=0x7fdf98011a00, stream=...) at /usr/src/debug/akonadi-16.12.2/src/private/protocol.cpp:3344
#14 0x00007fe0443709b4 in Akonadi::Protocol::operator<< (command=..., stream=...) at /usr/src/debug/akonadi-16.12.2/src/private/protocol.cpp:383
#15 Akonadi::Protocol::serialize (device=<optimized out>, command=...) at /usr/src/debug/akonadi-16.12.2/src/private/protocol.cpp:636
#16 0x000000000042cde3 in Akonadi::Server::Connection::sendResponse (this=0x1d6cef0, tag=1339, response=...) at /usr/src/debug/akonadi-16.12.2/src/server/connection.cpp:404
#17 0x0000000000431272 in Akonadi::Server::Handler::sendResponse (response=..., this=0x7fdf9800d160) at /usr/src/debug/akonadi-16.12.2/src/server/handler.cpp:268
#18 Akonadi::Server::Handler::sendResponse<Akonadi::Protocol::Response> (this=0x7fdf9800d160, response=...) at /usr/src/debug/akonadi-16.12.2/src/server/handler.h:152
#19 Akonadi::Server::Handler::failureResponse (this=this@entry=0x7fdf9800d160, failureMessage=...) at /usr/src/debug/akonadi-16.12.2/src/server/handler.cpp:261
#20 0x000000000043142f in Akonadi::Server::Handler::failureResponse (this=0x7fdf9800d160, failureMessage=<optimized out>) at /usr/src/debug/akonadi-16.12.2/src/server/handler.cpp:252
#21 0x000000000042efbd in Akonadi::Server::Connection::slotNewData (this=0x1d6cef0) at /usr/src/debug/akonadi-16.12.2/src/server/connection.cpp:252
#22 0x00007fe0434a1a7e in QtPrivate::QSlotObjectBase::call (a=0x7fdfb97f98d0, r=0x1d6cef0, this=<optimized out>) at ../../src/corelib/kernel/qobject_impl.h:101
#23 QMetaObject::activate (sender=0x7fdf98002cd0, signalOffset=<optimized out>, local_signal_index=<optimized out>, argv=<optimized out>) at kernel/qobject.cpp:3723
#24 0x00007fe0434a1709 in QMetaObject::activate (sender=0x7fdf98002dc8, signalOffset=<optimized out>, local_signal_index=<optimized out>, argv=<optimized out>) at kernel/qobject.cpp:3740
#25 0x00007fe0440ac265 in ?? () from /usr/lib64/libQt5Network.so.5
#26 0x00007fe0440ac31c in ?? () from /usr/lib64/libQt5Network.so.5
#27 0x00007fe0440b7121 in ?? () from /usr/lib64/libQt5Network.so.5
#28 0x00007fe043475aeb in doNotify (event=0x7fdfb97f9ae0, receiver=0x7fdf98003060) at kernel/qcoreapplication.cpp:1063
#29 QCoreApplication::notify (event=<optimized out>, receiver=<optimized out>, this=<optimized out>) at kernel/qcoreapplication.cpp:1049
#30 QCoreApplication::notifyInternal2 (receiver=0x7fdf98003060, event=event@entry=0x7fdfb97f9ae0) at kernel/qcoreapplication.cpp:988
#31 0x00007fe0434ca61d in QCoreApplication::sendEvent (event=0x7fdfb97f9ae0, receiver=<optimized out>) at ../../src/corelib/kernel/qcoreapplication.h:231
#32 socketNotifierSourceDispatch (source=0x7fdf98002a00) at kernel/qeventdispatcher_glib.cpp:106
#33 0x00007fe03f5ab697 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#34 0x00007fe03f5ab900 in ?? () from /usr/lib64/libglib-2.0.so.0
#35 0x00007fe03f5ab9ac in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#36 0x00007fe0434ca16f in QEventDispatcherGlib::processEvents (this=0x7fdf980008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#37 0x00007fe043473aea in QEventLoop::exec (this=this@entry=0x7fdfb97f9d00, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#38 0x00007fe0432a1813 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:507
#39 0x00007fe0432a64c8 in QThreadPrivate::start (arg=0x1d69380) at thread/qthread_unix.cpp:368
#40 0x00007fe0417c8454 in start_thread (arg=0x7fdfb97fa700) at pthread_create.c:333
#41 0x00007fe04299c37f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105