The new compiled Qt Creator 3.3 will crash immediately when launch it on my kubuntu 14.10.

The new compiled Qt Creator 3.3 will crash immediately when launch it on my kubuntu 14.10. And here is the core stack:

gemfield@CivilNet:~$ gdb ~/QtCreator/build/bin/qtcreator core
GNU gdb (Ubuntu 7.8-0ubuntu1) 7.8
...
Reading symbols from /home/gemfield/QtCreator/build/bin/qtcreator...done.
[New LWP 22428]
[New LWP 22429]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `/home/gemfield/QtCreator/build/bin/qtcreator'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f583a0855f7 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/KDEPlatformTheme.so
(gdb) bt
#0 0x00007f583a0855f7 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/KDEPlatformTheme.so
#1 0x00007f584443871c in QApplicationPrivate::initializeWidgetFontHash () at /home/gemfield/Qt/qt5/qtbase/src/widgets/kernel/qapplication.cpp:710
#2 0x00007f58444379cd in qt_init (priv=0x9b6eb0, type=1) at /home/gemfield/Qt/qt5/qtbase/src/widgets/kernel/qapplication.cpp:600
#3 0x00007f584443796d in QApplicationPrivate::construct (this=0x9b6eb0) at /home/gemfield/Qt/qt5/qtbase/src/widgets/kernel/qapplication.cpp:576
#4 0x00007f5844437917 in QApplication::QApplication (this=0x7fff9f6e7200, argc=@0x7fff9f6e6bec: 1, argv=0x7fff9f6e7368, _internal=328960)
at /home/gemfield/Qt/qt5/qtbase/src/widgets/kernel/qapplication.cpp:563
#5 0x0000000000407163 in SharedTools::QtSingleApplication::QtSingleApplication (this=0x7fff9f6e7200, appId=..., argc=@0x7fff9f6e6bec: 1, argv=0x7fff9f6e7368)
at ../../../qt-creator/src/shared/qtsingleapplication/qtsingleapplication.cpp:57
#6 0x000000000040c5d5 in main (argc=1, argv=0x7fff9f6e7368) at ../../../qt-creator/src/app/main.cpp:302