Hudson Jelly file is failing to render internal tag

This Code is from a Hudson plugin. The problem is that the line

<aspen:featureTable support="${it.getLastBuild().getFeatureSupport()}" />

should render to a table inside the following script. does anyone know why it would be skipped over by the r开发者_C百科endering engine?

<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
  <l:layout xmlns:aspen="hudson/plugins/aspen/tags">
    <st:include it="${it.project}" page="sidepanel.jelly" />
    <l:main-panel>
        <h1>${it.project.getName()} : ${it.getLastBuild().getFeatureSupport().getDisplayName()}</h1>
        <aspen:featureTable support="${it.getLastBuild().getFeatureSupport()}" />
    </l:main-panel>
  </l:layout>
</j:jelly>

The inner tag fails to render for atleast two non-obvious reasons. One that an exception has occurred during run time evaluation. Two the xmlns declared needs to include an empty file called "taglib"