tst_QGLThreads::textureUploadInThread flakily crashes on macOS 10.11

agent:2018/02/13 11:45:06 build.go:396: Executing instruction 709 of 1058 - RunQtUnitTest
agent:2018/02/13 11:45:06 build.go:263: [make check -j1] 900 900
/Users/qt/work/qt/qtbase/tests/auto/opengl/qglthreads/target_wrapper.sh  ./tst_qglthreads -o /Users/qt/work/testresults/tests/auto/opengl/qglthreads624314417,xml -o -,txt
********* Start testing of tst_QGLThreads *********
Config: Using QtTest library 5.11.0, Qt 5.11.0 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 8.0.0 (clang-800.0.42.1) (Apple))
PASS   : tst_QGLThreads::initTestCase()
PASS   : tst_QGLThreads::swapInThread()
QFATAL : tst_QGLThreads::textureUploadInThread() Cannot make QOpenGLContext current in a different thread
FAIL!  : tst_QGLThreads::textureUploadInThread() Received a fatal error.
   Loc: [Unknown file(0)]
Totals: 2 passed, 1 failed, 0 skipped, 0 blacklisted, 10131ms
********* Finished testing of tst_QGLThreads *********
make: *** [check] Abort trap: 6

agent:2018/02/13 11:45:17 build.go:187: Process finished with error: exit status 2
agent:2018/02/13 11:45:17 build.go:139: Error reading from stdout/err: exit status 2
agent:2018/02/13 11:45:37 build.go:263: [make check -j1] 900 900