Improve log message when adding an empty Git repository

2013-01-15 13:24:33,301 INFO - [example--repo] starting initial scan of repository
2013-01-15 13:24:34,339 WARN - Could not create .mailmap file for git repository 'example--repo'. Committers will not be mapped.
com.atlassian.fisheye.dvcs.handler.DvcsProcessException: Error while communicating with VCS: fatal: Not a valid object name HEAD

at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:214)
at com.atlassian.fisheye.git.GitScanner.updateMailMap(GitScanner.java:277)
at com.atlassian.fisheye.git.GitScanner.performClone(GitScanner.java:245)
at com.atlassian.fisheye.dvcs.DvcsScanner.cloneRepo(DvcsScanner.java:173)
at com.atlassian.fisheye.dvcs.DvcsScanner.updateClone(DvcsScanner.java:149)
at com.atlassian.fisheye.dvcs.DvcsScanner.updateLocalRepoCache(DvcsScanner.java:143)
at com.cenqua.fisheye.rep.BaseRepositoryScanner.ping(BaseRepositoryScanner.java:179)
at com.cenqua.fisheye.rep.BaseRepositoryEngine.doSlurp(BaseRepositoryEngine.java:92)
at com.cenqua.fisheye.rep.RepositoryEngine.slurp(RepositoryEngine.java:383)
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:619)
Caused by: com.atlassian.utils.process.ProcessException: While executing: "/opt/bcs/bin/git ls-tree HEAD – .mailmap " in [/cm/fisheye/data/var/cache/example--repo/clone]
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)
... 16 more
Caused by: com.atlassian.utils.process.ProcessException: Non-zero exit code: 128
at com.atlassian.utils.process.PluggableProcessHandler.complete(PluggableProcessHandler.java:83)
at com.atlassian.utils.process.ExternalProcessImpl.finish(ExternalProcessImpl.java:308)
at com.atlassian.utils.process.ExternalProcessImpl.execute(ExternalProcessImpl.java:351)
at com.atlassian.fisheye.dvcs.client.DvcsContext.executeCommand(DvcsContext.java:259)
... 18 more
2013-01-15 13:24:35,735 INFO - [example--repo] finished initial scan of repository in 1s{