Version:            (using KDE Devel)
Installed from:    Compiled sources

KRunner crashes from time to time, as I saw especialy if you execute commands that are not recognized by it from .desktop files (eg. nvidia-settings, kicker from KDE3, own shell scripts). It doesn't always happen.
Here is the BT:
[?1034hUsing host libthread_db library "/lib64/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 47271393888992 (LWP 12049)]
[New Thread 1115720016 (LWP 12191)]
[New Thread 1107327312 (LWP 12190)]
[New Thread 1098934608 (LWP 12189)]
[New Thread 1090541904 (LWP 12188)]
[New Thread 1082149200 (LWP 12187)]
[KCrash handler]
#5  0x00002afe36764b45 in raise () from /lib64/libc.so.6
#6  0x00002afe367660e0 in abort () from /lib64/libc.so.6
#7  0x00002afe31e76c3e in qt_message_output (msgType=QtFatalMsg, 
    buf=0x7fff7c228380 "ASSERT: \"!isEmpty()\" in file ../../include/QtCore/../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qlist.h, line 243")
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/global/qglobal.cpp:2160
#8  0x00002afe31e76d4d in qFatal (
    msg=0x2afe31f6a518 "ASSERT: \"%s\" in file %s, line %d")
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/global/qglobal.cpp:2392
#9  0x00002afe31e76e8b in qt_assert (assertion=0x2afe31f9b915 "!isEmpty()", 
    file=0x2afe31f9b888 "../../include/QtCore/../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qlist.h", line=243)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/global/qglobal.cpp:1917
#10 0x00002afe31edb691 in QList<QByteArray>::first (this=0x7819f8)
    at ../../include/QtCore/../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qlist.h:243
#11 0x00002afe31edb724 in QRingBuffer::nextDataBlockSize (this=0x7819f8)
    at ../../include/QtCore/private/../../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qringbuffer_p.h:63
#12 0x00002afe31edb7e6 in QRingBuffer::free (this=0x7819f8, bytes=0)
    at ../../include/QtCore/private/../../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qringbuffer_p.h:76
#13 0x00002afe31edb9a8 in QRingBuffer::read (this=0x7819f8, data=0x0, 
    maxLength=1126874)
    at ../../include/QtCore/private/../../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qringbuffer_p.h:235
#14 0x00002afe31edb9d6 in QRingBuffer::skip (this=0x7819f8, length=1126874)
    at ../../include/QtCore/private/../../../../../../sources/kde-trunk/qt-copy/src/corelib/tools/qringbuffer_p.h:274
#15 0x00002afe31edf90e in QIODevice::seek (this=0x8c5080, pos=1713797)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/io/qiodevice.cpp:621
#16 0x00002afe31ecb4a4 in QBuffer::seek (this=0x8c5080, pos=1713797)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/io/qbuffer.cpp:379
#17 0x00002afe314c93b9 in KSycocaDict::Private::offsetForKey (this=0x785230, 
    key=@0x7fff7c22a770)
    at /data/development/sources/kde-trunk/kdelibs/kdecore/sycoca/ksycocadict.cpp:518
#18 0x00002afe314ca408 in KSycocaDict::find_string (this=0x7a69c0, 
    key=@0x7fff7c22a770)
    at /data/development/sources/kde-trunk/kdelibs/kdecore/sycoca/ksycocadict.cpp:142
#19 0x00002afe3144f3ce in KServiceFactory::findServiceByDesktopName (
    this=0x7cf2a0, _name=@0x7fff7c22a770)
    at /data/development/sources/kde-trunk/kdelibs/kdecore/services/kservicefactory.cpp:116
#20 0x00002afe31448e48 in KService::serviceByDesktopName (
    _name=@0x7fff7c22a800)
    at /data/development/sources/kde-trunk/kdelibs/kdecore/services/kservice.cpp:549
#21 0x00002afe30db3000 in KRun::runCommand (cmd=@0x7fff7c22a8b0, 
    execName=@0x7fff7c22a870, iconName=@0x7fff7c22a870, window=0x0, 
    asn=@0x7fff7c22a880)
    at /data/development/sources/kde-trunk/kdelibs/kio/kio/krun.cpp:788
#22 0x00002afe30db30b3 in KRun::runCommand (cmd=@0x7fff7c22a8b0, window=0x0)
    at /data/development/sources/kde-trunk/kdelibs/kio/kio/krun.cpp:779
#23 0x00002afe2eab5cb3 in ShellRunner::exec (this=<value optimized out>, 
    action=<value optimized out>)
    at /data/development/sources/kde-trunk/kdebase/workspace/krunner/runners/shell/shellrunner.cpp:70
#24 0x00002afe2eaae3ef in Interface::matchActivated (this=0x6e9fc0, 
    item=<value optimized out>)
    at /data/development/sources/kde-trunk/kdebase/workspace/krunner/interface.cpp:78
#25 0x00002afe2eaaef66 in Interface::exec (this=0x6e9fc0)
    at /data/development/sources/kde-trunk/kdebase/workspace/krunner/interface.cpp:623
#26 0x00002afe2eab19f4 in Interface::updateMatches (this=0x6e9fc0)
    at /data/development/sources/kde-trunk/kdebase/workspace/krunner/interface.cpp:597
#27 0x00002afe2eab1b6d in Interface::qt_metacall (this=0x6e9fc0, 
    _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, 
    _a=0x7fff7c22b120)
    at /data/development/build/kde-trunk/kdebase/workspace/krunner/interface.moc:93
#28 0x00002afe31f4475d in QMetaObject::activate (sender=0x6ea028, 
    from_signal_index=4, to_signal_index=4, argv=0x0)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qobject.cpp:3087
#29 0x00002afe31f45101 in QMetaObject::activate (sender=0x6ea028, 
    m=0x2afe321fa300, local_signal_index=0, argv=0x0)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qobject.cpp:3149
#30 0x00002afe31f69700 in QTimer::timeout (this=0x6ea028)
    at .moc/debug-shared/moc_qtimer.cpp:125
#31 0x00002afe31f4d466 in QTimer::timerEvent (this=0x6ea028, e=0x7fff7c22ba70)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qtimer.cpp:259
#32 0x00002afe31f4244a in QObject::event (this=0x6ea028, e=0x7fff7c22ba70)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qobject.cpp:1095
#33 0x00002afe34339285 in QApplicationPrivate::notify_helper (this=0x62c960, 
    receiver=0x6ea028, e=0x7fff7c22ba70)
    at /data/development/sources/kde-trunk/qt-copy/src/gui/kernel/qapplication.cpp:3556
#34 0x00002afe343395a7 in QApplication::notify (this=0x62c3e0, 
    receiver=0x6ea028, e=0x7fff7c22ba70)
    at /data/development/sources/kde-trunk/qt-copy/src/gui/kernel/qapplication.cpp:3115
#35 0x00002afe2fb52506 in KApplication::notify (this=0x62c3e0, 
    receiver=0x6ea028, event=0x7fff7c22ba70)
    at /data/development/sources/kde-trunk/kdelibs/kdeui/kernel/kapplication.cpp:314
#36 0x00002afe31f30c50 in QCoreApplication::notifyInternal (this=0x62c3e0, 
    receiver=0x6ea028, event=0x7fff7c22ba70)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qcoreapplication.cpp:530
#37 0x00002afe31f33e4d in QCoreApplication::sendEvent (receiver=0x6ea028, 
    event=0x7fff7c22ba70)
    at ../../include/QtCore/../../../../../sources/kde-trunk/qt-copy/src/corelib/kernel/qcoreapplication.h:200
#38 0x00002afe31f5c4f3 in QTimerInfoList::activateTimers (this=0x630ec0)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qeventdispatcher_unix.cpp:554
#39 0x00002afe31f59ca7 in timerSourceDispatch (source=0x630e60)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qeventdispatcher_glib.cpp:155
#40 0x00002afe37e2a204 in g_main_context_dispatch ()
   from /usr/lib64/libglib-2.0.so.0
#41 0x00002afe37e2d4fd in ?? () from /usr/lib64/libglib-2.0.so.0
#42 0x00002afe37e2d9ce in g_main_context_iteration ()
   from /usr/lib64/libglib-2.0.so.0
#43 0x00002afe31f58c25 in QEventDispatcherGlib::processEvents (this=0x62cb00, 
    flags=@0x7fff7c22bca0)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qeventdispatcher_glib.cpp:340
#44 0x00002afe343ca487 in QGuiEventDispatcherGlib::processEvents (
    this=0x62cb00, flags=@0x7fff7c22bcf0)
    at /data/development/sources/kde-trunk/qt-copy/src/gui/kernel/qguieventdispatcher_glib.cpp:191
#45 0x00002afe31f2ddf1 in QEventLoop::processEvents (this=0x7fff7c22bda0, 
    flags=@0x7fff7c22bd50)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qeventloop.cpp:140
#46 0x00002afe31f2df46 in QEventLoop::exec (this=0x7fff7c22bda0, 
    flags=@0x7fff7c22bdb0)
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qeventloop.cpp:182
#47 0x00002afe31f313ca in QCoreApplication::exec ()
    at /data/development/sources/kde-trunk/qt-copy/src/corelib/kernel/qcoreapplication.cpp:759
#48 0x00002afe34338e5c in QApplication::exec ()
    at /data/development/sources/kde-trunk/qt-copy/src/gui/kernel/qapplication.cpp:3053
#49 0x00002afe2eab4015 in kdemain (argc=1, argv=0x7fff7c22c058)
    at /data/development/sources/kde-trunk/kdebase/workspace/krunner/main.cpp:53
#50 0x00002afe36751b54 in __libc_start_main () from /lib64/libc.so.6
#51 0x0000000000400959 in _start ()
#0  0x00002afe367ca6a1 in nanosleep () from /lib64/libc.so.6