Trying to diagnose a random test failure.
=== Starting demo(org.jenkinsci.plugins.workflow.WorkflowTest)
=== Starting demo(org.jenkinsci.plugins.workflow.WorkflowTest)
java.util.concurrent.ExecutionException: java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.FutureTask@1c685fb2 rejected from java.util.concurrent.ThreadPoolExecutor@862adb0[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 6]
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:188)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$3.get(CpsThreadGroup.java:230)
	at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.waitForSuspension(CpsFlowExecution.java:449)
	at org.jenkinsci.plugins.workflow.SingleJobTestBase.waitForWorkflowToSuspend(SingleJobTestBase.java:97)
	at org.jenkinsci.plugins.workflow.SingleJobTestBase.waitForWorkflowToComplete(SingleJobTestBase.java:88)
	at org.jenkinsci.plugins.workflow.WorkflowTest$2.evaluate(WorkflowTest.java:93)
	at org.jvnet.hudson.test.RestartableJenkinsRule$3.evaluate(RestartableJenkinsRule.java:84)
	at org.jvnet.hudson.test.JenkinsRule$2.evaluate(JenkinsRule.java:480)
	at org.jvnet.hudson.test.RestartableJenkinsRule.run(RestartableJenkinsRule.java:100)
	at org.jvnet.hudson.test.RestartableJenkinsRule.access$100(RestartableJenkinsRule.java:30)
	at org.jvnet.hudson.test.RestartableJenkinsRule$1.evaluate(RestartableJenkinsRule.java:64)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
	at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)
Caused by: java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.FutureTask@1c685fb2 rejected from java.util.concurrent.ThreadPoolExecutor@862adb0[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 6]
	at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2048)
	at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:821)
	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1372)
	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:110)
	at java.util.concurrent.Executors$DelegatedExecutorService.submit(Executors.java:638)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:174)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:166)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:744)