tst_controls crash after a warning at Default::SwipeDelegate::test_display()

agent:2018/09/14 02:44:15 build.go:193: /home/qt/work/qt/qtquickcontrols2/tests/auto/controls/default/target_wrapper.sh  ./tst_default -o /home/qt/work/testresults/tests/auto/controls/default635380209,xml -o -,txt
agent:2018/09/14 02:44:15 build.go:193: ********* Start testing of tst_controls::Default *********
agent:2018/09/14 02:44:15 build.go:193: Config: Using QtTest library 5.12.0, Qt 5.12.0 (x86_64-little_endian-lp64 shared (dynamic) debug build; by GCC 8.2.0)
agent:2018/09/14 02:44:15 build.go:193: PASS   : tst_controls::Default::AbstractButton::initTestCase()
...
agent:2018/09/14 02:45:00 build.go:193: PASS   : tst_controls::Default::SwipeDelegate::test_delegateWidth()
agent:2018/09/14 02:45:00 build.go:193: QWARN  : tst_controls::Default::SwipeDelegate::test_display() Previously registered enum will be overwritten due to name clash: QQuickSwipeDelegate.Left
agent:2018/09/14 02:45:00 build.go:193: Makefile:326: recipe for target 'check' failed
agent:2018/09/14 02:45:00 build.go:193: make: *** [check] Segmentation fault (core dumped)
agent:2018/09/14 02:45:00 build.go:237: Process finished with error: exit status 2
agent:2018/09/14 02:45:00 build.go:196: Error reading from stdout/err: exit status 2
...