"fatal: git upload-pack: not our ref" errors

2014-08-18 23:28:11,256 WARN  [ssh-scm-request-handler]  c.a.s.i.s.s.SshScmRequestCommandAdapter Exception encountered handling SSH command 'git-upload-pack '/INFRA/puppet-master.git''
java.io.IOException: git process terminated with exit code 128 and error 'fatal: git upload-pack: not our ref 7e18bf90f45cd6bdf14a39ee7dfd64a81fdb1015
'
        at com.atlassian.stash.scm.cache.ssh.UploadPackProxy.setServerStateOrThrow(UploadPackProxy.java:308) ~[na:na]
        at com.atlassian.stash.scm.cache.ssh.UploadPackProxy.streamPack(UploadPackProxy.java:224) ~[na:na]
        at com.atlassian.stash.scm.cache.ssh.CachingSshUploadPackRequest.bypassCache(CachingSshUploadPackRequest.java:283) ~[na:na]
        at com.atlassian.stash.scm.cache.ssh.CachingSshUploadPackRequest.handleRequest(CachingSshUploadPackRequest.java:176) ~[na:na]
        at com.atlassian.stash.internal.ssh.server.SshScmRequestCommandAdapter$ScmRequestRunnable$1.withRequest(SshScmRequestCommandAdapter.java:289) ~[stash-ssh-3.3.0-m11_1407928730000.jar:na]
        at com.atlassian.stash.internal.ssh.server.SshScmRequestCommandAdapter$ScmRequestRunnable$1.withRequest(SshScmRequestCommandAdapter.java:277) ~[stash-ssh-3.3.0-m11_1407928730000.jar:na]
        at com.atlassian.stash.internal.request.DefaultRequestManager.doAsRequest(DefaultRequestManager.java:84) ~[DefaultRequestManager.class:na]
        at com.atlassian.stash.internal.ssh.server.SshScmRequestCommandAdapter$ScmRequestRunnable.run(SshScmRequestCommandAdapter.java:277) ~[stash-ssh-3.3.0-m11_1407928730000.jar:na]
        at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64) [stash-ssh-3.3.0-m11_1407928730000.jar:na]
        at com.atlassian.stash.internal.concurrent.StateTransferringExecutor$StateTransferringRunnable.run(StateTransferringExecutor.java:69) [StateTransferringExecutor$StateTransferringRunnable.class:na]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [na:1.7.0_60]
        at java.util.concurrent.FutureTask.run(FutureTask.java:262) [na:1.7.0_60]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178) [na:1.7.0_60]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292) [na:1.7.0_60]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_60]
        at java.lang.Thread.run(Thread.java:745) [na:1.7.0_60]
        ... 26 frames trimmed