Crash at the end of Qt Quick Extras auto test

-input /home/micurtis/dev/qt5.6/qtquickcontrols/tests/auto/extras/data/tst_delaybutton.qml

0	QV4::Value::operator=	qv4value_p.h	380	0x7ffff53ccc0f	
1	QV4::MemoryManager::sweep	qv4mm.cpp	389	0x7ffff53cba00	
2	QV4::MemoryManager::~MemoryManager	qv4mm.cpp	552	0x7ffff53cc949	
3	QV4::ExecutionEngine::~ExecutionEngine	qv4engine.cpp	465	0x7ffff55181db	
4	QV8Engine::~QV8Engine	qv8engine.cpp	161	0x7ffff56b0da4	
5	QV8Engine::~QV8Engine	qv8engine.cpp	162	0x7ffff56b0e30	
6	QJSEngine::~QJSEngine	qjsengine.cpp	213	0x7ffff5499f6a	
7	QQmlEngine::~QQmlEngine	qqmlengine.cpp	935	0x7ffff55fd71a	
8	QQmlEngine::~QQmlEngine	qqmlengine.cpp	959	0x7ffff55fd74a	
9	QObjectPrivate::deleteChildren	qobject.cpp	1954	0x7ffff6aa079c	
10	QObject::~QObject	qobject.cpp	1034	0x7ffff6a9ee4e	
11	QWindow::~QWindow	qwindow.cpp	203	0x7ffff6f802e8	
12	QQuickWindow::~QQuickWindow	qquickwindow.cpp	1109	0x7ffff5b361fb	
13	QQuickView::~QQuickView	qquickview.cpp	223	0x7ffff5c20525	
14	QQuickView::~QQuickView	qquickview.cpp	230	0x7ffff5c2055e	
15	quick_test_main	quicktest.cpp	397	0x7ffff7fd8f7d	
16	main	tst_extras.cpp	39	0x403e0a