This happened on the nightly integration tests, but did not happen during the continuous integration tests. So while I'm not sure how repeatable it is, there is at least a stack trace:

java.lang.IllegalStateException: Failed to initialize the repository with text content.
at org.jboss.dna.jcr.DnaRepositoryStub.configureRepository(DnaRepositoryStub.java:140)
at org.jboss.dna.jcr.DnaRepositoryStub.getRepository(DnaRepositoryStub.java:157)
at org.jboss.dna.jcr.DnaRepositoryStub.getRepository(DnaRepositoryStub.java:41)
at org.apache.jackrabbit.test.RepositoryHelper.getRepository(RepositoryHelper.java:68)
at org.apache.jackrabbit.test.RepositoryHelper.getProperty(RepositoryHelper.java:150)
at org.apache.jackrabbit.test.AbstractJCRTest.getProperty(AbstractJCRTest.java:442)
at org.apache.jackrabbit.test.AbstractJCRTest.setUp(AbstractJCRTest.java:264)
at org.apache.jackrabbit.test.api.RootNodeTest.setUp(RootNodeTest.java:47)
at junit.framework.TestCase.runBare(TestCase.java:132)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at org.apache.jackrabbit.test.AbstractJCRTest.run(AbstractJCRTest.java:406)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:81)
at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:62)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:140)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:127)
at org.apache.maven.surefire.Surefire.run(Surefire.java:177)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:345)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1009)
Caused by: java.lang.NullPointerException
at org.jboss.dna.graph.search.SearchEngineIndexer.indexSubgraph(SearchEngineIndexer.java:294)
at org.jboss.dna.graph.search.SearchEngineIndexer.index(SearchEngineIndexer.java:227)
at org.jboss.dna.graph.search.SearchEngineIndexer.index(SearchEngineIndexer.java:135)
at org.jboss.dna.jcr.RepositoryQueryManager$SelfContained.reindexContent(RepositoryQueryManager.java:334)
at org.jboss.dna.jcr.RepositoryQueryManager$SelfContained.<init>(RepositoryQueryManager.java:292)
at org.jboss.dna.jcr.JcrRepository.<init>(JcrRepository.java:593)
at org.jboss.dna.jcr.JcrEngine.doCreateJcrRepository(JcrEngine.java:257)
at org.jboss.dna.jcr.JcrEngine.getRepository(JcrEngine.java:175)
at org.jboss.dna.jcr.DnaRepositoryStub.configureRepository(DnaRepositoryStub.java:120)
at org.jboss.dna.jcr.DnaRepositoryStub.getRepository(DnaRepositoryStub.java:157)
at org.jboss.dna.jcr.DnaRepositoryStub.getRepository(DnaRepositoryStub.java:41)
at org.apache.jackrabbit.test.RepositoryHelper.getRepository(RepositoryHelper.java:68)
at org.apache.jackrabbit.test.RepositoryHelper.getProperty(RepositoryHelper.java:150)
at org.apache.jackrabbit.test.AbstractJCRTest.getProperty(AbstractJCRTest.java:442)
at org.apache.jackrabbit.test.AbstractJCRTest.setUp(AbstractJCRTest.java:264)
at org.apache.jackrabbit.test.api.RootNodeTest.setUp(RootNodeTest.java:47)
at junit.framework.TestCase.runBare(TestCase.java:132)