After opening a qtdeclarative build, I got a crash. This is not completely reproducable, but happened at least twice when opening a new project that was not open in creator before. After re-starting creator the project is there and seems just fine. (The crash happens at least with the 2.8 branch built against Qt 5.2 - dev branch, Linux).

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fff4aaf9700 (LWP 15484)]
0x00007fffdf957643 in QHashNode<ProKey, ProStringList>::same_key (this=0x6f006d80000000, h0=247715322, key0=...)
at /home/frederik/dev/qt/qt-creator/qtbase/include/QtCore/../../../../qt-src-creator/qtbase/src/corelib/tools/qhash.h:215
215 inline bool same_key(uint h0, const Key &key0) const

(gdb) bt
#0 0x00007fffdf957643 in QHashNode<ProKey, ProStringList>::same_key (this=0x6f006d80000000, h0=247715322, key0=...)
at /home/frederik/dev/qt/qt-creator/qtbase/include/QtCore/../../../../qt-src-creator/qtbase/src/corelib/tools/qhash.h:215
#1 0x00007fffdf9556b6 in QHash<ProKey, ProStringList>::findNode (this=0x7ffefd1509d0, akey=..., ahp=0x7fff4aaf8abc)
at /home/frederik/dev/qt/qt-creator/qtbase/include/QtCore/../../../../qt-src-creator/qtbase/src/corelib/tools/qhash.h:918
#2 0x00007fffdf952c0a in QHash<ProKey, ProStringList>::operator[] (this=0x7ffefd1509d0, akey=...)
at /home/frederik/dev/qt/qt-creator/qtbase/include/QtCore/../../../../qt-src-creator/qtbase/src/corelib/tools/qhash.h:767
#3 0x00007fffdf94ab11 in QMakeEvaluator::setupProject (this=0x7486eb0)
at /home/frederik/dev/qt/qt-src-creator/qt-creator/src/shared/proparser/qmakeevaluator.cpp:1238
#4 0x00007fffdf94b6e9 in QMakeEvaluator::visitProFile (this=0x7486eb0, pro=0x7ffef3559800, type=QMakeHandler::EvalProjectFile, flags=...)
at /home/frederik/dev/qt/qt-src-creator/qt-creator/src/shared/proparser/qmakeevaluator.cpp:1362
#5 0x00007fffdf95b560 in ProFileEvaluator::accept (this=0x2c4fdc8, pro=0x7ffef3559800, flags=...)
at /home/frederik/dev/qt/qt-src-creator/qt-creator/src/shared/proparser/profileevaluator.cpp:198
#6 0x00007fffded22851 in Qt4ProjectManager::Qt4ProFileNode::evaluate (this=0x37a23c0)
at /home/frederik/dev/qt/qt-src-creator/qt-creator/src/plugins/qt4projectmanager/qt4nodes.cpp:1581
#7 0x00007fffded228e8 in Qt4ProjectManager::Qt4ProFileNode::asyncEvaluate (this=0x37a23c0, fi=...)
at /home/frederik/dev/qt/qt-src-creator/qt-creator/src/plugins/qt4projectmanager/qt4nodes.cpp:1594
#8 0x00007fffded39e79 in QtConcurrent::StoredInterfaceMemberFunctionCall0<Qt4ProjectManager::Qt4ProFileNode::EvalResult, void (Qt4ProjectManager::Qt4ProFileNode::*)(QFutureInterface<Qt4ProjectManager::Qt4ProFileNode::EvalResult>&), Qt4ProjectManager::Qt4ProFileNode>::run (this=0x3fac160)
at /home/frederik/dev/qt/qt-src-creator/qt-creator/src/libs/utils/runextensions.h:83
#9 0x00007ffff5ef81cf in QThreadPoolThread::run (this=0x7ffef832b490) at /home/frederik/dev/qt/qt-src-creator/qtbase/src/corelib/thread/qthreadpool.cpp:100
#10 0x00007ffff5efe1a5 in QThreadPrivate::start (arg=0x7ffef832b490) at /home/frederik/dev/qt/qt-src-creator/qtbase/src/corelib/thread/qthread_unix.cpp:345
#11 0x00007ffff5c41f8e in start_thread (arg=0x7fff4aaf9700) at pthread_create.c:311
#12 0x00007ffff5452e1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113