Test failure: ObservationRefreshTest

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 16.174 sec <<< FAILURE!
observation[0](org.apache.jackrabbit.oak.jcr.observation.ObservationRefreshTest)  Time elapsed: 16.173 sec  <<< ERROR!
javax.jcr.InvalidItemStateException: OakMerge0001: OakMerge0001: Failed to merge changes to the underlying store (retries 5, 5286 ms)
	at org.apache.jackrabbit.oak.api.CommitFailedException.asRepositoryException(CommitFailedException.java:239)
	at org.apache.jackrabbit.oak.api.CommitFailedException.asRepositoryException(CommitFailedException.java:212)
	at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.newRepositoryException(SessionDelegate.java:664)
	at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.save(SessionDelegate.java:489)
	at org.apache.jackrabbit.oak.jcr.session.SessionImpl$8.performVoid(SessionImpl.java:424)
	at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.performVoid(SessionDelegate.java:268)
	at org.apache.jackrabbit.oak.jcr.session.SessionImpl.save(SessionImpl.java:421)
	at org.apache.jackrabbit.oak.jcr.observation.ObservationRefreshTest.observation(ObservationRefreshTest.java:176)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:30)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.junit.runners.Suite.runChild(Suite.java:128)
	at org.junit.runners.Suite.runChild(Suite.java:24)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
	at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
	at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: org.apache.jackrabbit.oak.api.CommitFailedException: OakMerge0001: OakMerge0001: Failed to merge changes to the underlying store (retries 5, 5286 ms)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge0(DocumentNodeStoreBranch.java:242)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge(DocumentNodeStoreBranch.java:179)
	at org.apache.jackrabbit.oak.plugins.document.DocumentRootBuilder.merge(DocumentRootBuilder.java:158)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.merge(DocumentNodeStore.java:1451)
	at org.apache.jackrabbit.oak.core.MutableRoot.commit(MutableRoot.java:247)
	at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.commit(SessionDelegate.java:341)
	at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.save(SessionDelegate.java:487)
	... 43 more
Caused by: org.apache.jackrabbit.oak.plugins.document.DocumentStoreException: The node 3:/oak:index/nodetype/:index was already added in revision
r14d31a418d3-0-1, before
r14d31a44656-0-1
	at org.apache.jackrabbit.oak.plugins.document.Commit.checkConflicts(Commit.java:524)
	at org.apache.jackrabbit.oak.plugins.document.Commit.createOrUpdateNode(Commit.java:438)
	at org.apache.jackrabbit.oak.plugins.document.Commit.applyToDocumentStore(Commit.java:341)
	at org.apache.jackrabbit.oak.plugins.document.Commit.applyToDocumentStore(Commit.java:246)
	at org.apache.jackrabbit.oak.plugins.document.Commit.applyInternal(Commit.java:215)
	at org.apache.jackrabbit.oak.plugins.document.Commit.apply(Commit.java:200)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:323)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:293)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.access$200(DocumentNodeStoreBranch.java:52)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch$InMemory.merge(DocumentNodeStoreBranch.java:530)
	at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge0(DocumentNodeStoreBranch.java:219)