tst_QGuiEventLoop::testQuitLock() is flaky on macOS 10.12

Module "qt/qtbase" (eb6547b2808513c7b9822b18d8ccf2eb487b42d1) Failed test(s): /Users/qt/work/qt/qtbase/tests/auto/gui/kernel/qguieventloop:
 agent:2017/06/19 07:16:22 build.go:344: Executing instruction 407 of 940
 agent:2017/06/19 07:16:22 build.go:270: [make check -j1] 900 1200
 /Users/qt/work/qt/qtbase/tests/auto/gui/kernel/qguieventloop/target_wrapper.sh  ./tst_qguieventloop -o /Users/qt/work/testresults/tests/auto/gui/kernel/qguieventloop235985366,xml -o -,txt
 ********* Start testing of tst_QGuiEventLoop *********
 Config: Using QtTest library 5.9.1, Qt 5.9.1 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 8.0.0 (clang-800.0.42.1) (Apple))
 PASS   : tst_QGuiEventLoop::initTestCase()
 BPASS  : tst_QGuiEventLoop::processEvents()
 QWARN  : tst_QGuiEventLoop::exec() QEventLoop::exec: instance 0x7fff55b46ae8 has already called exec()
 PASS   : tst_QGuiEventLoop::exec()
 PASS   : tst_QGuiEventLoop::reexec()
 PASS   : tst_QGuiEventLoop::execAfterExit()
 PASS   : tst_QGuiEventLoop::wakeUp()
 PASS   : tst_QGuiEventLoop::quit()
 PASS   : tst_QGuiEventLoop::processEventsExcludeSocket()
 XFAIL  : tst_QGuiEventLoop::processEventsExcludeTimers() X11ExcludeTimers only supported in the UNIX/Glib dispatchers
    Loc: [../../../corelib/kernel/qeventloop/tst_qeventloop.cpp(524)]
 PASS   : tst_QGuiEventLoop::processEventsExcludeTimers()
 PASS   : tst_QGuiEventLoop::deliverInDefinedOrder()
 PASS   : tst_QGuiEventLoop::nestedLoops()
 FAIL!  : tst_QGuiEventLoop::testQuitLock() 'timerSpy.count() > 3' returned FALSE. ()
    Loc: [../../../corelib/kernel/qeventloop/tst_qeventloop.cpp(660)]
 PASS   : tst_QGuiEventLoop::cleanupTestCase()
 Totals: 11 passed, 1 failed, 0 skipped, 1 blacklisted, 5532ms
 ********* Finished testing of tst_QGuiEventLoop *********
 make: *** [check] Error 1
 
 agent:2017/06/19 07:16:27 build.go:200: Process finished with error: exit status 2
 agent:2017/06/19 07:16:27 build.go:152: Error reading from stdout/err: exit status 2
 agent:2017/06/19 07:16:47 build.go:270: [make check -j1] 900 1200
 /Users/qt/work/qt/qtbase/tests/auto/gui/kernel/qguieventloop/target_wrapper.sh  ./tst_qguieventloop testQuitLock
 ********* Start testing of tst_QGuiEventLoop *********
 Config: Using QtTest library 5.9.1, Qt 5.9.1 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 8.0.0 (clang-800.0.42.1) (Apple))
 PASS   : tst_QGuiEventLoop::initTestCase()
 QDEBUG : tst_QGuiEventLoop::testQuitLock() 18
 PASS   : tst_QGuiEventLoop::testQuitLock()
 PASS   : tst_QGuiEventLoop::cleanupTestCase()
 Totals: 3 passed, 0 failed, 0 skipped, 0 blacklisted, 3289ms
 ********* Finished testing of tst_QGuiEventLoop *********
 
 agent:2017/06/19 07:16:52 build.go:270: [make check -j1] 900 1200
 /Users/qt/work/qt/qtbase/tests/auto/gui/kernel/qguieventloop/target_wrapper.sh  ./tst_qguieventloop testQuitLock
 ********* Start testing of tst_QGuiEventLoop *********
 Config: Using QtTest library 5.9.1, Qt 5.9.1 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 8.0.0 (clang-800.0.42.1) (Apple))
 PASS   : tst_QGuiEventLoop::initTestCase()
 QDEBUG : tst_QGuiEventLoop::testQuitLock() 16
 FAIL!  : tst_QGuiEventLoop::testQuitLock() 'timerSpy.count() > 17' returned FALSE. ()
    Loc: [../../../corelib/kernel/qeventloop/tst_qeventloop.cpp(678)]
 PASS   : tst_QGuiEventLoop::cleanupTestCase()
 Totals: 2 passed, 1 failed, 0 skipped, 0 blacklisted, 3142ms
 ********* Finished testing of tst_QGuiEventLoop *********
 make: *** [check] Error 1
 
 agent:2017/06/19 07:16:55 build.go:200: Process finished with error: exit status 2
 agent:2017/06/19 07:16:55 build.go:152: Error reading from stdout/err: exit status 2
 agent:2017/06/19 07:16:55 build.go:334: Found core file(s), uploading.
 agent:2017/06/19 07:16:55 storageclient.go:489: Creating artifacts archive and uploading it
 agent:2017/06/19 07:16:55 storageclient.go:511: Archive starts at directory /cores
 agent:2017/06/19 07:21:28 agent.go:167: Test failed
 agent:2017/06/19 07:21:28 agent.go:121: ERROR building: exit status 2
 Build log: https://testresults.qt.io/logs/qt/qtbase/255052c7ed8a177799bb5fcb8580622a0e5a2050/MacOSMacOS_10_12x86_64MacOSMacOS_10_12x86_64Clangqtci-macos-10.12-x86_64-8-9339dbDebugAndRelease_Release/7ca30f915833d953146007e71743147e3e719500/test_1497843259/testlog.txt.gz
 Details: https://testresults.qt.io/coin/integration/qt/qtbase/tasks/1497843235