I am trying to be able to step through the code of a Hudson plugin called SVNPublisher. I checked out the code for SVNPublisher, used Netbeans to open the project, and clicked "Debug Main project". This results in a Firefox window opening address http://localhost:8080 which shows the Hudson main page. Clicking the "New Job" link results in an error page:

HTTP ERROR: 500

jar:file:/home/francis/svn/svnpublisher/target/work/webapp/WEB-INF/lib/hudson-core-1.319.jar!/lib/hudson/newFromList/form.jelly:43:47: <j:forEach> hudson.scm.SubversionTagAction and hudson.scm.SubversionTagAction$DescriptorImpl disagree on InnerClasses attribute

RequestURI=/newJob
Caused by:

org.apache.commons.jelly.JellyTagException: jar:file:/home/francis/svn/svnpublisher/target/work/webapp/WEB-INF/lib/hudson-core-1.319.jar!/lib/hudson/newFromList/form.jelly:43:47:  hudson.scm.SubversionTagAction and hudson.scm.SubversionTagAction$DescriptorImpl disagree on InnerClasses attribute
    at org.apache.commons.jelly.impl.TagScript.handleException(TagScript.java:713)
    at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:282)
    at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
    ...

I am very new to Hudson and not very experienced with Java so I'm pretty much clueless on the meaning of this error.

Can anyone help?