build failed without reason, with log as follows

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 56 seconds
[INFO] Finished at: Wed Aug 03 17:32:04 CST 2011
[INFO] Final Memory: 75M/714M
[INFO] ------------------------------------------------------------------------
FATAL: null
java.lang.NullPointerException
at hudson.plugins.analysis.core.HealthAwareReporter.end(HealthAwareReporter.java:281)
at hudson.maven.MavenBuild$RunnerImpl.post2(MavenBuild.java:778)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:604)
at hudson.model.Run.run(Run.java:1400)
at hudson.maven.MavenBuild.run(MavenBuild.java:275)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:175)