Sometimes when pausing the game, a segfault occurs.
Below is the stacktrace:

Program received signal SIGSEGV, Segmentation fault.
0x0016a0ff in QAbstractAnimation::state (this=0x81332c8) at animation/qabstractanimation.cpp:463
463 return d->state;
(gdb) bt
#0 0x0016a0ff in QAbstractAnimation::state (this=0x81332c8) at animation/qabstractanimation.cpp:463
#1 0x0805e8f7 in AnimationManager::pauseAll (this=0x81a0640) at animationmanager.cpp:81
#2 0x0805ff3d in PauseState::onEntry (this=0x84f3dc8) at states.cpp:207
#3 0x002fe83f in QAbstractStatePrivate::callOnEntry (this=0x84f3050, e=0x850af80) at statemachine/qabstractstate.cpp:110
#4 0x002ee0a3 in QStateMachinePrivate::enterStates (this=0x847d4d8, event=0x850af80, enabledTransitions=...) at statemachine/qstatemachine.cpp:515
#5 0x002ed5a4 in QStateMachinePrivate::microstep (this=0x847d4d8, event=0x850af80, enabledTransitions=...) at statemachine/qstatemachine.cpp:375
#6 0x002f1b11 in QStateMachinePrivate::_q_process (this=0x847d4d8) at statemachine/qstatemachine.cpp:1278
#7 0x002f1f1d in QStateMachinePrivate::processEvents (this=0x847d4d8, processingMode=QStateMachinePrivate::DirectProcessing)
at statemachine/qstatemachine.cpp:1357