Missing parent on one side of a merge fails indexing process

@  changeset:   2:b0dab59e7170
|  tag:         tip
|  parent:      -1:000000000000
|  parent:      1:b010b6b432a7
|  user:        admin
|  date:        Wed May 09 01:01:56 2012 -0500
|  summary:     merge XXXXXXXXXXXXXXXXXXXXXXXX to default
|
o  changeset:   1:b010b6b432a7
|  branch:      XXXXXXXXXXXXXXXXXXXXXXXX
|  user:        user_abc
|  date:        Wed May 09 00:58:13 2012 -0500
|  summary:     A summary.
|
o  changeset:   0:4d795be6f9a4
   branch:      XXXXXXXXXXXXXXXXXXXXXXXX
   user:        user_abc
   date:        Wed May 09 00:54:53 2012 -0500
   summary:     A summary. fixing build errors.

2012-05-09 01:13:54,195 INFO [IncrementalPinger1 test_crash] fisheye.app BaseRepositoryScanner-doSlurpTransaction - Starting slurp of test_crash
2012-05-09 01:13:55,832 ERROR [IncrementalPinger1 test_crash] fisheye.app BaseRepositoryScanner-handleSlurpException - Problem processing revisions from repo test_crash due to class com.cenqua.fisheye.rep.RepositoryClientException - com.atlassian.fisheye.dvcs.handler.DvcsProcessException: Error while communicating with VCS:
com.cenqua.fisheye.rep.RepositoryClientException: com.atlassian.fisheye.dvcs.handler.DvcsProcessException: Error while communicating with VCS:
at com.atlassian.fisheye.dvcs.DvcsScanner.processRevisions(DvcsScanner.java:299)
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)
Caused by: com.atlassian.fisheye.dvcs.handler.DvcsProcessException: Error while communicating with VCS:
at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:214)
at com.atlassian.fisheye.hg.HgScanner.processChange(HgScanner.java:232)
at com.atlassian.fisheye.hg.HgScanner.slurpCommits(HgScanner.java:221)
at com.atlassian.fisheye.dvcs.DvcsScanner.processBranch(DvcsScanner.java:415)
at com.atlassian.fisheye.hg.HgScanner.processBranch(HgScanner.java:305)
at com.atlassian.fisheye.dvcs.DvcsScanner.processRevisions(DvcsScanner.java:243)
... 13 more
Caused by: com.atlassian.utils.process.ProcessException: While executing: "/usr/bin/hg --config extensions.felog=/home/crucible/fecru-2.7.11/python/hg/hgfelog/hgfelog.py --config ui.verbose=false felog b0dab59e71706a135eaadefbaeb9467909f80700 -p -m "
at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:262)
at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:254)
at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:212)
... 18 more
Caused by: com.atlassian.utils.process.ProcessException: java.lang.RuntimeException: Match failed: string [P: b010b6b432a783c2758b793fc5a79f65e784cfd4], pattern [M:(.*)]
at com.atlassian.utils.process.ExternalProcessImpl$4.doTask(ExternalProcessImpl.java:273)
at com.atlassian.utils.process.LatchedRunnable.run(LatchedRunnable.java:25)
... 3 more
Caused by: java.lang.RuntimeException: Match failed: string [P: b010b6b432a783c2758b793fc5a79f65e784cfd4], pattern [M:(.*)]
at com.atlassian.fisheye.hg.client.HgChangeParser.processLine(HgChangeParser.java:247)
at com.atlassian.utils.process.LineOutputHandler.process(LineOutputHandler.java:49)
at com.atlassian.utils.process.LineOutputHandler.process(LineOutputHandler.java:36)
at com.atlassian.utils.process.PluggableProcessHandler.processOutput(PluggableProcessHandler.java:34)
at com.atlassian.utils.process.ExternalProcessImpl$4.doTask(ExternalProcessImpl.java:270)
... 4 more