Missing changesets cause Hg indexing to fail

2012-05-24 15:21:53,707 ERROR [InitialPinger1 Mainline] fisheye.app DvcsScanner$1-perform - Could not find change set for commit 90ca09564cd8ebd6638b5ea93916d4a6af2e683d
2012-05-24 15:21:53,709 DEBUG [InitialPinger1 Mainline] perf.timer Timer-output - <- Indexing changesets of Mainline  time 69216 micros mem_usage = 122857440 heapsize = 165625856 freemem = 42768416
2012-05-24 15:21:53,787 DEBUG [InitialPinger1 Mainline] fisheye.app LoggingProcessMonitor-onBeforeStart - Starting process: hg --config ui.verbose=false tags 
2012-05-24 15:21:54,120 DEBUG [InitialPinger1 Mainline] fisheye.app LoggingProcessMonitor-onAfterFinished - Finished process: hg --config ui.verbose=false tags  took 333ms
2012-05-24 15:21:54,120 DEBUG [InitialPinger1 Mainline] fisheye.app DvcsCache-getLongHash - getLongHash: Illegal argument: null
2012-05-24 15:21:54,122 DEBUG [InitialPinger1 Mainline] fisheye.app LoggingProcessMonitor-onBeforeStart - Starting process: hg --config extensions.felog=C:\crucible\python\hg\hgfelog\hgfelog.py -v feparents null 
2012-05-24 15:21:54,122 DEBUG [InitialPinger1 Mainline] fisheye.app LoggingProcessMonitor-onAfterFinished - Finished process: hg --config extensions.felog=C:\crucible\python\hg\hgfelog\hgfelog.py -v feparents null  took 0ms
2012-05-24 15:21:54,124 ERROR [InitialPinger1 Mainline] fisheye.app BaseRepositoryScanner-handleSlurpException - Problem processing revisions from repo Mainline due to class java.lang.NullPointerException - null
java.lang.NullPointerException
	at com.atlassian.utils.process.ExternalProcessImpl.quoteString(ExternalProcessImpl.java:157)
	at com.atlassian.utils.process.ExternalProcessImpl.createWinProcess(ExternalProcessImpl.java:210)
	at com.atlassian.utils.process.ExternalProcessImpl.createProcess(ExternalProcessImpl.java:223)
	at com.atlassian.utils.process.ExternalProcessImpl.start(ExternalProcessImpl.java:238)
	at com.atlassian.utils.process.ExternalProcessImpl.execute(ExternalProcessImpl.java:350)
	at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:259)
	at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:254)
	at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:212)
	at com.atlassian.fisheye.hg.client.HgClientManifestDAO.visitRevisions(HgClientManifestDAO.java:53)
	at com.atlassian.fisheye.hg.HgCache.applyTag(HgCache.java:267)
	at com.atlassian.fisheye.hg.HgScanner.processTag(HgScanner.java:202)
	at com.atlassian.fisheye.hg.HgScanner.processTags(HgScanner.java:165)
	at com.atlassian.fisheye.dvcs.DvcsScanner.processRevisions(DvcsScanner.java:287)
	at com.cenqua.fisheye.rep.BaseRepositoryScanner.slurpRepository(BaseRepositoryScanner.java:257)
	at com.cenqua.fisheye.rep.BaseRepositoryScanner.doSlurpTransaction(BaseRepositoryScanner.java:225)
	at com.cenqua.fisheye.rep.BaseRepositoryScanner.ping(BaseRepositoryScanner.java:184)
	at com.cenqua.fisheye.rep.BaseRepositoryEngine.doSlurp(BaseRepositoryEngine.java:92)
	at com.cenqua.fisheye.rep.RepositoryEngine.slurp(RepositoryEngine.java:381)
	at com.cenqua.fisheye.rep.ping.OneOffPingRequest.doRequest(OneOffPingRequest.java:28)
	at com.cenqua.fisheye.rep.ping.PingRequest.process(PingRequest.java:67)
	at com.cenqua.fisheye.rep.RepositoryHandle.processPingRequests(RepositoryHandle.java:138)
	at com.cenqua.fisheye.rep.RepositoryHandle.queuePingRequest(RepositoryHandle.java:128)
	at com.cenqua.fisheye.rep.ping.PingRequest.run(PingRequest.java:33)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)
2012-05-24 15:21:54,128 DEBUG [InitialPinger1 Mainline] fisheye.app RepositoryStatus-setEngineError - Engine Error Set [Mainline]: Repository index failed due to error
java.lang.NullPointerException: null
2012-05-24 15:21:54,128 DEBUG [InitialPinger1 Mainline] fisheye.app BaseRepositoryScanner-doSlurpTransaction - Rolling back cache changes
2012-05-24 15:21:54,128 INFO  [InitialPinger1 Mainline] fisheye.perf BaseRepositoryScanner-ping - done slurp for /Mainline time = 865137ms