Since 4.8.1 Kontact seems to crash more often when selecting emails (which in turn are shown in the preview pane). This happened several times now. Seems to be some interaction with nepomuk...
Maybe this is related but possibly not: before the crashes I was trying to go to the next/previous message via keyboard shortcut which is not working anymore since 4.8.1. 


Application: Kontact (kontact), signal: Aborted
[Current thread is 1 (Thread 0x7fb8f1ab2760 (LWP 3517))]

Thread 5 (Thread 0x7fb8d9224700 (LWP 3518)):
#0  0x00007fb8e993fe6c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fb8ee2cec12 in WTF::TCMalloc_PageHeap::scavengerThread (this=0x7fb8eec6d1a0) at ../../../Source/JavaScriptCore/wtf/FastMalloc.cpp:2495
#2  0x00007fb8ee2cec49 in WTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../../../Source/JavaScriptCore/wtf/FastMalloc.cpp:1618
#3  0x00007fb8e993bf05 in start_thread () from /lib64/libpthread.so.0
#4  0x00007fb8eefbe63d in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7fb8d890b700 (LWP 3519)):
#0  0x00007fb8eefb5523 in poll () from /lib64/libc.so.6
#1  0x00007fb8e942ca98 in ?? () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fb8e942cf59 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fb8ef72c956 in QEventDispatcherGlib::processEvents (this=0x7fb8d40008c0, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:426
#4  0x00007fb8ef6fc682 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fb8ef6fc8d7 in QEventLoop::exec (this=0x7fb8d890ae20, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007fb8ef5fd537 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#7  0x00007fb8ef60055b in QThreadPrivate::start (arg=0x77f650) at thread/qthread_unix.cpp:298
#8  0x00007fb8e993bf05 in start_thread () from /lib64/libpthread.so.0
#9  0x00007fb8eefbe63d in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7fb88bcd5700 (LWP 3916)):
#0  0x00007fb8eefcb83e in __lll_lock_wait_private () from /lib64/libc.so.6
#1  0x00007fb8eef5f9d9 in _L_lock_3352 () from /lib64/libc.so.6
#2  0x00007fb8eef5a7db in _int_free () from /lib64/libc.so.6
#3  0x00007fb8e944720f in ?? () from /usr/lib64/libglib-2.0.so.0
#4  0x00007fb8e94473fd in ?? () from /usr/lib64/libglib-2.0.so.0
#5  0x00007fb8e993bca3 in __nptl_deallocate_tsd () from /lib64/libpthread.so.0
#6  0x00007fb8e993bf13 in start_thread () from /lib64/libpthread.so.0
#7  0x00007fb8eefbe63d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7fb88adaa700 (LWP 3918)):
[KCrash Handler]
#9  0x00007fb8eef59f3a in malloc_consolidate () from /lib64/libc.so.6
#10 0x00007fb8eef5b123 in _int_malloc () from /lib64/libc.so.6
#11 0x00007fb8eef5dd6e in malloc () from /lib64/libc.so.6
#12 0x00007fb8ef602558 in QByteArray::realloc (this=0x7fb87c009ea8, alloc=65504) at tools/qbytearray.cpp:1452
#13 0x00007fb8ef602679 in QByteArray::resize (this=0x7fb87c009ea8, size=32768) at tools/qbytearray.cpp:1420
#14 0x00007fb8ea8da986 in reserve (bytes=2, this=0x7fb87c009e30) at ../../src/corelib/tools/qringbuffer_p.h:158
#15 QAbstractSocket::writeData (this=<optimized out>, data=0x7fb88ada964c "\021", size=2) at socket/qabstractsocket.cpp:2315
#16 0x00007fb8ef69082f in QIODevice::write (this=0x7fb87c007180, data=0x7fb88ada964c "\021", maxSize=<optimized out>) at io/qiodevice.cpp:1370
#17 0x00007fb8e2bfcbd5 in Soprano::DataStream::writeUnsignedInt16 (this=0x7fb88ada9670, v=17) at /usr/src/debug/soprano-2.7.4/server/datastream.cpp:95
#18 0x00007fb8e2c03d6a in Soprano::Client::ClientConnection::executeQuery (this=0xf0a9b0, modelId=2118209818, query=..., type=Soprano::Query::QueryLanguageSparql, userQueryLanguage=...) at /usr/src/debug/soprano-2.7.4/client/clientconnection.cpp:263
#19 0x00007fb8e2c058b3 in Soprano::Client::ClientModel::executeQuery (this=<optimized out>, query=<optimized out>, language=<optimized out>, userQueryLanguage=<optimized out>) at /usr/src/debug/soprano-2.7.4/client/clientmodel.cpp:101
#20 0x00007fb8e719364c in Nepomuk::MainModel::executeQuery (this=0xf08de0, query=..., language=Soprano::Query::QueryLanguageSparql, userQueryLanguage=...) at /usr/src/debug/kdelibs-4.8.1/nepomuk/core/nepomukmainmodel.cpp:212
#21 0x00007fb8e717feb3 in Nepomuk::ResourceData::load (this=0x7fb87c0096e0) at /usr/src/debug/kdelibs-4.8.1/nepomuk/core/resourcedata.cpp:417
#22 0x00007fb8e71807bc in Nepomuk::ResourceData::property (this=0x7fb87c0096e0, uri=...) at /usr/src/debug/kdelibs-4.8.1/nepomuk/core/resourcedata.cpp:265
#23 0x00007fb8e71967e3 in Nepomuk::Resource::property (this=0x7fb88ada9d20, uri=...) at /usr/src/debug/kdelibs-4.8.1/nepomuk/core/resource.cpp:301
#24 0x00007fb8907710ca in MessageCore::NepomukResourceRetrieverRunnable::run (this=0x1ebc640) at /usr/src/debug/kdepim-4.8.1/messagecore/asyncnepomukresourceretriever.cpp:47
#25 0x00007fb8ef5f3d12 in QThreadPoolThread::run (this=0x18114a0) at concurrent/qthreadpool.cpp:107
#26 0x00007fb8ef60055b in QThreadPrivate::start (arg=0x18114a0) at thread/qthread_unix.cpp:298
#27 0x00007fb8e993bf05 in start_thread () from /lib64/libpthread.so.0
#28 0x00007fb8eefbe63d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7fb8f1ab2760 (LWP 3517)):
[KCrash Handler]
#6  0x00007fb8eef19d95 in raise () from /lib64/libc.so.6
#7  0x00007fb8eef1b2ab in abort () from /lib64/libc.so.6
#8  0x00007fb8eef53ece in __libc_message () from /lib64/libc.so.6
#9  0x00007fb8eef59c06 in malloc_printerr () from /lib64/libc.so.6
#10 0x00007fb8ec13554e in qMetaTypeDeleteHelper<QDBusMessage> (t=0x12a6780) at ../../src/corelib/kernel/qmetatype.h:134
#11 0x00007fb8ef70dd79 in QMetaCallEvent::~QMetaCallEvent (this=0x1eeb510, __in_chrg=<optimized out>) at kernel/qobject.cpp:509
#12 0x00007fb8ef70ddd9 in QMetaCallEvent::~QMetaCallEvent (this=0x1eeb510, __in_chrg=<optimized out>) at kernel/qobject.cpp:518
#13 0x00007fb8ef701143 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x60da60) at kernel/qcoreapplication.cpp:1516
#14 0x00007fb8ef72c4c3 in sendPostedEvents () at kernel/qcoreapplication.h:236
#15 postEventSourceDispatch (s=<optimized out>) at kernel/qeventdispatcher_glib.cpp:279
#16 0x00007fb8e942c58d in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#17 0x00007fb8e942cd88 in ?? () from /usr/lib64/libglib-2.0.so.0
#18 0x00007fb8e942cf59 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#19 0x00007fb8ef72c8ef in QEventDispatcherGlib::processEvents (this=0x60d320, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#20 0x00007fb8f01b42de in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=<optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#21 0x00007fb8ef6fc682 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#22 0x00007fb8ef6fc8d7 in QEventLoop::exec (this=0x7fff5addd3e0, flags=...) at kernel/qeventloop.cpp:204
#23 0x00007fb8ef701435 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#24 0x0000000000403919 in ?? ()
#25 0x00007fb8eef0623d in __libc_start_main () from /lib64/libc.so.6
#26 0x0000000000403e51 in _start ()