2020-06-25 04:34:19,098 ERROR [farm-operation-4]  c.a.b.i.m.m.f.t.ReplyingTopicListener Error while processing request TopicRequest{message=RefChangeChunk{farmSynchronizationRequest=FarmSynchronizationRequest{externalRepositoryId=345, type=snapshot}, last=true, index=0, digest=..., payload.length=...}, replyTopic=refChangeChunk_..._reply, anticipatedResponders=1}
java.lang.RuntimeException: Unexpected error generating a list of changes
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.refchange.RefChangeCalculator.localDiff(RefChangeCalculator.java:83)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.synchronization.RepositorySynchronizationOperation.perform(RepositorySynchronizationOperation.java:111)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.synchronization.RepositorySynchronizationOperation.perform(RepositorySynchronizationOperation.java:39)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.topic.operation.MetricCollectingMirrorOperation.perform(MetricCollectingMirrorOperation.java:66)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.refchange.RefChangeChunkOperation.perform(RefChangeChunkOperation.java:100)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.refchange.RefChangeChunkOperation.perform(RefChangeChunkOperation.java:62)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.topic.operation.MetricCollectingMirrorOperation.perform(MetricCollectingMirrorOperation.java:66)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.topic.operation.AuthenticatedMirrorOperation.lambda$perform$0(AuthenticatedMirrorOperation.java:37)
        at com.atlassian.stash.internal.user.DefaultEscalatedSecurityContext.call(DefaultEscalatedSecurityContext.java:58)
        at com.atlassian.bitbucket.internal.mirroring.mirror.DefaultUpstreamUserHelper.performAsUpstreamUser(DefaultUpstreamUserHelper.java:93)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.topic.operation.AuthenticatedMirrorOperation.perform(AuthenticatedMirrorOperation.java:37)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.topic.operation.MultiThreadedMirrorOperation.lambda$perform$0(MultiThreadedMirrorOperation.java:45)
        at com.google.common.util.concurrent.TrustedListenableFutureTask$TrustedFutureInterruptibleTask.runInterruptibly(TrustedListenableFutureTask.java:125)
        at com.google.common.util.concurrent.InterruptibleTask.run(InterruptibleTask.java:57)
        at com.google.common.util.concurrent.TrustedListenableFutureTask.run(TrustedListenableFutureTask.java:78)
        at com.atlassian.sal.core.executor.ThreadLocalDelegateRunnable.run(ThreadLocalDelegateRunnable.java:34)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.lang.Thread.run(Thread.java:748)
        ... 1 frame trimmed
Caused by: com.atlassian.bitbucket.ServerException: An error occurred while executing an external process: process timed out
        at com.atlassian.bitbucket.scm.git.command.GitCommandExitHandler.evaluateThrowable(GitCommandExitHandler.java:120)
        at com.atlassian.bitbucket.scm.git.command.GitCommandExitHandler.onError(GitCommandExitHandler.java:208)
        at com.atlassian.bitbucket.scm.DefaultCommandExitHandler.onExit(DefaultCommandExitHandler.java:32)
        at com.atlassian.bitbucket.scm.BaseCommand.callExitHandler(BaseCommand.java:214)
        at com.atlassian.bitbucket.scm.BaseCommand$CommandFuture.internalGet(BaseCommand.java:348)
        at com.atlassian.bitbucket.scm.BaseCommand$CommandFuture.get(BaseCommand.java:312)
        at com.atlassian.bitbucket.scm.BaseCommand.call(BaseCommand.java:144)
        at com.atlassian.bitbucket.internal.mirroring.mirror.farm.refchange.RefChangeCalculator.localDiff(RefChangeCalculator.java:81)
        ... 18 common frames omitted
Caused by: com.atlassian.utils.process.ProcessTimeoutException: process timed out
        at com.atlassian.utils.process.ExternalProcessImpl.wrapUpProcess(ExternalProcessImpl.java:664)
        at com.atlassian.utils.process.ExternalProcessImpl.finish(ExternalProcessImpl.java:163)
        at com.atlassian.bitbucket.scm.BaseCommand$CommandFuture.get(BaseCommand.java:310)
        ... 20 common frames omitted