title: GWT Maven Archetype in Eclipse - Unknown output directory
body: <p>I've created a new Maven project using the gwt-maven-plugin archetype in Eclipse Juno.
  After creating the project I get a build error:</p>
  
  <blockquote>
    <p>Unknown   Google Web App Problem: The output directory for the project
    should be set to /myproject/src/main/webapp/WEB-INF/classes</p>
  </blockquote>
  
  <p>How do I resolve this?</p>