title: Why does maven install fail during javadoc generation?
body: <p>When running 'maven install', I get the following..</p>
  
  <blockquote>
    <p>[INFO] [javadoc:javadoc {execution:
    default}] [INFO]
    ------------------------------------------------------------------------ [ERROR] BUILD ERROR [INFO]
    ------------------------------------------------------------------------ [INFO] An error has occurred in
    JavaDocs report generation:Exit code:
    1 - java.lang.NullPointerException
            at com.sun.tools.doclets.formats.html.PackageUseWriter.generatePackageUse(PackageUseWriter.java:180)
            at com.sun.tools.doclets.formats.html.PackageUseWriter.generatePackageList(PackageUseWriter.java:124)
            at com.sun.tools.doclets.formats.html.PackageUseWriter.generatePackageUse(PackageUseWriter.java:110)
            at com.sun.tools.doclets.formats.html.PackageUseWriter.generatePackageUseFile(PackageUseWriter.java:99)
            at com.sun.tools.doclets.formats.html.PackageUseWriter.generate(PackageUseWriter.java:78)
            at com.sun.tools.doclets.formats.html.ClassUseWriter.generate(ClassUseWriter.java:116)
            at com.sun.tools.doclets.formats.html.HtmlDoclet.generateOtherFiles(HtmlDoclet.java:92)
            at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.startGeneration(AbstractDoclet.java:122)
            at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.start(AbstractDoclet.java:64)
            at com.sun.tools.doclets.formats.html.HtmlDoclet.start(HtmlDoclet.java:42)
            at com.sun.tools.doclets.standard.Standard.start(Standard.java:23)
            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 com.sun.tools.javadoc.DocletInvoker.invoke(DocletInvoker.java:269)
            at com.sun.tools.javadoc.DocletInvoker.start(DocletInvoker.java:143)
            at com.sun.tools.javadoc.Start.parseAndExecute(Start.java:340)
            at com.sun.tools.javadoc.Start.begin(Start.java:128)
            at com.sun.tools.javadoc.Main.execute(Main.java:41)
            at com.sun.tools.javadoc.Main.main(Main.java:31)</p>
  </blockquote>
  
  <p>Command line was: <code>/home/fsl/jdk1.6.0_12/jre/../bin/javadoc @options @packages @argfile</code></p>
  
  <p>What am I doing wrong?</p>