Random NullPointerException in org.jboss.weld.tests.experimental.event.async.executor.FireAsyncWithExecutorTest

Sometimes I am getting an exception during building Weld on master branch:

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 2.058 sec <<< FAILURE! - in org.jboss.weld.tests.experimental.event.async.executor.FireAsyncWithExecutorTest
testGivenExecutorUsed(org.jboss.weld.tests.experimental.event.async.executor.FireAsyncWithExecutorTest) Time elapsed: 2.024 sec <<< ERROR!
java.lang.NullPointerException: null
at org.jboss.weld.tests.experimental.event.async.executor.FireAsyncWithExecutorTest.testGivenExecutorUsed(FireAsyncWithExecutorTest.java:69)