From time to time, on various builds, I see this exception. Can you please look at why this might occur?

-----------------------------------------------------------------------------
[INFO] Building expense-bridge domain service
[INFO] task-segment: [install]
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] null
[INFO] ------------------------------------------------------------------------
[INFO] Trace
java.lang.NullPointerException
at org.codehaus.plexus.component.configurator.converters.lookup.DefaultConverterLookup.findConverterForType(DefaultConverterLookup.java:115)
at org.codehaus.plexus.component.configurator.converters.lookup.DefaultConverterLookup.lookupConverterForType(DefaultConverterLookup.java:92)
at org.codehaus.plexus.component.configurator.converters.composite.CollectionConverter.fromConfiguration(CollectionConverter.java:175)
at org.codehaus.plexus.component.configurator.converters.ComponentValueSetter.configure(ComponentValueSetter.java:247)
at org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter.processConfiguration(ObjectWithFieldsConverter.java:137)
at org.codehaus.plexus.component.configurator.BasicComponentConfigurator.configureComponent(BasicComponentConfigurator.java:56)
at org.codehaus.plexus.component.configurator.AbstractComponentConfigurator.configureComponent(AbstractComponentConfigurator.java:54)
at org.codehaus.plexus.component.configurator.AbstractComponentConfigurator.configureComponent(AbstractComponentConfigurator.java:47)
at org.codehaus.plexus.personality.plexus.lifecycle.phase.AutoConfigurePhase.execute(AutoConfigurePhase.java:39)
at org.codehaus.plexus.lifecycle.AbstractLifecycleHandler.start(AbstractLifecycleHandler.java:101)
at org.codehaus.plexus.component.manager.AbstractComponentManager.startComponentLifecycle(AbstractComponentManager.java:105)
at org.codehaus.plexus.component.manager.AbstractComponentManager.createComponentInstance(AbstractComponentManager.java:95)
at org.codehaus.plexus.component.manager.ClassicSingletonComponentManager.getComponent(ClassicSingletonComponentManager.java:92)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:331)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:312)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:440)
at hudson.maven.agent.ContainerFilter.lookup(ContainerFilter.java:89)
at hudson.maven.agent.PluginManagerInterceptor$1$1.lookup(PluginManagerInterceptor.java:95)
at org.apache.maven.plugin.DefaultPluginManager.getPluginComponent(DefaultPluginManager.java:1595)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.findExtension(DefaultLifecycleExecutor.java:1438)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.findMappingsForLifecycle(DefaultLifecycleExecutor.java:1346)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.bindLifecycleForPackaging(DefaultLifecycleExecutor.java:1292)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.constructLifecycleMappings(DefaultLifecycleExecutor.java:1275)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:534)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
at org.apache.maven.lifecycle.LifecycleExecutorInterceptor.execute(LifecycleExecutorInterceptor.java:65)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at hudson.maven.agent.Main.launch(Main.java:165)
at hudson.maven.MavenBuilder.call(MavenBuilder.java:165)
at hudson.maven.MavenModuleSetBuild$Builder.call(MavenModuleSetBuild.java:694)
at hudson.maven.MavenModuleSetBuild$Builder.call(MavenModuleSetBuild.java:638)
at hudson.remoting.UserRequest.perform(UserRequest.java:114)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:270)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4 seconds
[INFO] Finished at: Sun Oct 10 15:55:08 PDT 2010
[INFO] Final Memory: 7M/245M
[INFO] ------------------------------------------------------------------------