[2014-11-11 11:31:49,767] ERROR com.google.gerrit.server.git.ChangeMergeQueue : Merge attempt for TestRepoAaron,refs/heads/master failed
com.google.gerrit.server.git.MergeException: Cannot update refs/heads/master
    at com.google.gerrit.server.git.MergeOp.updateBranch(MergeOp.java:645)
    at com.google.gerrit.server.git.MergeOp.merge(MergeOp.java:252)
    at com.google.gerrit.server.git.ChangeMergeQueue$2.call(ChangeMergeQueue.java:210)
    at com.google.gerrit.server.git.ChangeMergeQueue$2.call(ChangeMergeQueue.java:207)
    at com.google.gerrit.server.util.RequestScopePropagator$5.call(RequestScopePropagator.java:222)
    at com.google.gerrit.server.util.RequestScopePropagator$4.call(RequestScopePropagator.java:201)
    at com.google.gerrit.server.git.PerThreadRequestScope$Propagator$1.call(PerThreadRequestScope.java:75)
    at com.google.gerrit.server.git.ChangeMergeQueue.mergeImpl(ChangeMergeQueue.java:207)
    at com.google.gerrit.server.git.ChangeMergeQueue.merge(ChangeMergeQueue.java:125)
    at com.google.gerrit.server.change.Submit.apply(Submit.java:176)
    at com.google.gerrit.server.change.Submit.apply(Submit.java:76)
    at com.google.gerrit.httpd.restapi.RestApiServlet.service(RestApiServlet.java:303)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at com.google.inject.servlet.ServletDefinition.doServiceImpl(ServletDefinition.java:278)
    at com.google.inject.servlet.ServletDefinition.doService(ServletDefinition.java:268)
    at com.google.inject.servlet.ServletDefinition.service(ServletDefinition.java:180)
    at com.google.inject.servlet.ManagedServletPipeline.service(ManagedServletPipeline.java:93)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:85)
    at com.google.gerrit.pgm.http.jetty.GetUserFilter.doFilter(GetUserFilter.java:76)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
    at com.google.gwtexpui.server.CacheControlFilter.doFilter(CacheControlFilter.java:70)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
    at com.google.gerrit.httpd.RunAsFilter.doFilter(RunAsFilter.java:113)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
    at com.google.gerrit.httpd.AllRequestFilter$FilterProxy$1.doFilter(AllRequestFilter.java:64)
    at com.google.gerrit.httpd.AllRequestFilter$FilterProxy.doFilter(AllRequestFilter.java:57)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
    at com.google.gerrit.httpd.RequestContextFilter.doFilter(RequestContextFilter.java:75)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
    at com.google.inject.servlet.ManagedFilterPipeline.dispatch(ManagedFilterPipeline.java:120)
    at com.google.inject.servlet.GuiceFilter$1.call(GuiceFilter.java:132)
    at com.google.inject.servlet.GuiceFilter$1.call(GuiceFilter.java:129)
    at com.google.inject.servlet.GuiceFilter$Context.call(GuiceFilter.java:206)
    at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:129)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1539)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:524)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:219)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1110)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:453)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1044)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
    at org.eclipse.jetty.server.handler.RequestLogHandler.handle(RequestLogHandler.java:92)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
    at org.eclipse.jetty.server.Server.handle(Server.java:459)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:280)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:229)
    at org.eclipse.jetty.io.AbstractConnection$1.run(AbstractConnection.java:505)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.io.IOException: Failure to replicate update. Output is:
    at org.eclipse.jgit.lib.RefUpdate.doReplicatedUpdate(RefUpdate.java:769)
    at org.eclipse.jgit.lib.RefUpdate.update(RefUpdate.java:508)
    at com.google.gerrit.server.git.MergeOp.updateBranch(MergeOp.java:611)
    ... 51 more