[Users] deploying ovirt-engine from src

[lof yer]

After following the steps in http://www.ovirt.org/Building_oVirt_engine, I
met some problems in deploying it.
Here's  the status while I visit
http://localhost:8700/webadmin/webadmin/WebAdmin.html
HTTP Status 500 -
------------------------------

*type* Exception report

*message*

*description* *The server encountered an internal error () that prevented
it from fulfilling this request.*

*exception*

javax.servlet.ServletException: Servlet execution threw an exception
	org.ovirt.engine.ui.frontend.server.gwt.GwtCachingFilter.doFilter(GwtCachingFilter.java:132)

*root cause*

java.lang.NoClassDefFoundError: Could not initialize class
org.ovirt.engine.ui.frontend.server.gwt.plugin.PluginDataManager$Holder
	org.ovirt.engine.ui.frontend.server.gwt.plugin.PluginDataManager.getInstance(PluginDataManager.java:74)
	org.ovirt.engine.ui.frontend.server.gwt.WebAdminHostPageServlet.getPluginData(WebAdminHostPageServlet.java:85)
	org.ovirt.engine.ui.frontend.server.gwt.WebAdminHostPageServlet.doGet(WebAdminHostPageServlet.java:53)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
	org.ovirt.engine.ui.frontend.server.gwt.GwtCachingFilter.doFilter(GwtCachingFilter.java:132)

*note* *The full stack trace of the root cause is available in the JBoss
Web/7.0.13.Final logs.*
------------------------------
JBoss Web/7.0.13.Final

What does it mean? And What should I do next?
Thanks!!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/users/attachments/20130407/b6b09fec/attachment-0001.html>