I have no idea about how this is happening. We have anightly build scheduled for
11PM of all modules in our maven 2 project. Most of this builds fail like this:

started
Reusing existing maven process
[INFO] Scanning for projects...
[INFO] ----------------------------------------------------------------------------
[INFO] Building Maven Default Project
[INFO] task-segment: [clean, install]
[INFO] ----------------------------------------------------------------------------
[HUDSON] Archiving null
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] null
[INFO] ------------------------------------------------------------------------
[INFO] Trace
java.lang.NullPointerException
at hudson.FilePath.<init>(FilePath.java:144)
at
hudson.maven.reporters.MavenArtifactArchiver.postBuild(MavenArtifactArchiver.java:63)
at
hudson.maven.PluginManagerInterceptor.postBuild(PluginManagerInterceptor.java:80)
at
org.apache.maven.lifecycle.LifecycleExecutorInterceptor.execute(LifecycleExecutorInterceptor.java:38)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:330)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:123)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:272)
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:585)
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:67)
at hudson.maven.MavenBuild$Builder.call(MavenBuild.java:160)
at hudson.maven.MavenBuild$Builder.call(MavenBuild.java:136)
at hudson.remoting.UserRequest.perform(UserRequest.java:57)
at hudson.remoting.UserRequest.perform(UserRequest.java:22)
at hudson.remoting.Request$2.run(Request.java:178)
at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)
[INFO] ------------------------------------------------------------------------
[INFO] Total time: < 1 second
[INFO] Finished at: Wed Apr 18 23:11:35 EST 2007
[INFO] Final Memory: 2M/4M
[INFO] ------------------------------------------------------------------------