TestSubWorkflowActionExecutor#testSubWorkflowRerun() is flaky

2018-10-19 09:43:39 [INFO] -------------------------------------------------------
2018-10-19 09:43:39 [INFO]  T E S T S
2018-10-19 09:43:39 [INFO] -------------------------------------------------------
2018-10-19 09:46:54 [INFO] Running org.apache.oozie.action.oozie.TestSubWorkflowActionExecutor
2018-10-19 09:46:54 [ERROR] Tests run: 15, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 194.156 s <<< FAILURE! - in org.apache.oozie.action.oozie.TestSubWorkflowActionExecutor
2018-10-19 09:46:54 [ERROR] testSubWorkflowRerun(org.apache.oozie.action.oozie.TestSubWorkflowActionExecutor)  Time elapsed: 103.736 s  <<< FAILURE!
2018-10-19 09:46:54 junit.framework.AssertionFailedError: expected:<SUCCEEDED> but was:<RUNNING>
2018-10-19 09:46:54 	at junit.framework.Assert.fail(Assert.java:57)
2018-10-19 09:46:54 	at junit.framework.Assert.failNotEquals(Assert.java:329)
2018-10-19 09:46:54 	at junit.framework.Assert.assertEquals(Assert.java:78)
2018-10-19 09:46:54 	at junit.framework.Assert.assertEquals(Assert.java:86)
2018-10-19 09:46:54 	at junit.framework.TestCase.assertEquals(TestCase.java:253)
2018-10-19 09:46:54 	at org.apache.oozie.action.oozie.TestSubWorkflowActionExecutor.testSubWorkflowRerun(TestSubWorkflowActionExecutor.java:580)
...
2018-10-19 09:46:54 [ERROR]   TestSubWorkflowActionExecutor.testSubWorkflowRerun:580 expected:<SUCCEEDED> but was:<RUNNING>