mvn clean site on the command line gives me no exceptions
running it in hudson with the findbugs plugin disabled gives me no exceptions
when enabling the plugin I have the following exception:

[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to configure plugin parameters for:
org.apache.maven.plugins:maven-site-plugin:2.0-beta-6

Cause: Cannot find setter nor field in org.apache.maven.plugins.site.SiteMojo
for 'xmlOutput'
[INFO] ------------------------------------------------------------------------
[DEBUG] Trace
org.apache.maven.lifecycle.LifecycleExecutionException: Error configuring:
org.apache.maven.plugins:maven-site-plugin. Reason: Unable to parse the created
DOM for plugin configuration
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:587)
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycle(DefaultLifecycleExecutor.java:499)
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:478)
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:330)
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:291)
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:142)
at
org.apache.maven.lifecycle.LifecycleExecutorInterceptor.execute(LifecycleExecutorInterceptor.java:42)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:336)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:129)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:287)
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:135)
at hudson.maven.MavenBuilder.call(MavenBuilder.java:139)
at hudson.maven.MavenModuleSetBuild$Builder.call(MavenModuleSetBuild.java:542)
at hudson.maven.MavenModuleSetBuild$Builder.call(MavenModuleSetBuild.java:488)
at hudson.remoting.UserRequest.perform(UserRequest.java:69)
at hudson.remoting.UserRequest.perform(UserRequest.java:23)
at hudson.remoting.Request$2.run(Request.java:213)
at java.util.concurrent.Executors$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$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: org.apache.maven.plugin.PluginConfigurationException: Error
configuring: org.apache.maven.plugins:maven-site-plugin. Reason: Unable to parse
the created DOM for plugin configuration
at
org.apache.maven.plugin.DefaultPluginManager.populatePluginFields(DefaultPluginManager.java:1288)
at
org.apache.maven.plugin.DefaultPluginManager.getConfiguredMojo(DefaultPluginManager.java:661)
at
org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:429)
at
hudson.maven.agent.PluginManagerInterceptor.executeMojo(PluginManagerInterceptor.java:159)
at
org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:558)
... 28 more
Caused by:
org.codehaus.plexus.component.configurator.ComponentConfigurationException:
Cannot find setter nor field in org.apache.maven.plugins.site.SiteMojo for
'xmlOutput'
at
org.codehaus.plexus.component.configurator.converters.ComponentValueSetter.<init>(ComponentValueSetter.java:68)
at
org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter.processConfiguration(ObjectWithFieldsConverter.java:134)
at
org.codehaus.plexus.component.configurator.BasicComponentConfigurator.configureComponent(BasicComponentConfigurator.java:56)
at
hudson.maven.agent.ComponentConfiguratorFilter.configureComponent(ComponentConfiguratorFilter.java:26)
at
hudson.maven.agent.PluginManagerInterceptor$MojoIntercepter.configureComponent(PluginManagerInterceptor.java:123)
at
org.apache.maven.plugin.DefaultPluginManager.populatePluginFields(DefaultPluginManager.java:1282)
... 32 more