Binding output port of p:choose

  Hi,

  I am trying to bind the result port of a p:choose/p:when to the
output port of my pipeline, which has another name:

    <p:declare-step xmlns:p="http://www.w3.org/ns/xproc"
                    name="pipeline"
                    version="1.0">

       <p:output port="my-result">
          <p:pipe port="result" step="s"/>
       </p:output>

       <p:choose name="s">
          <p:when test="true()">
             <p:identity>
                <p:input port="source">
                   <p:inline>
                      <true/>
                   </p:inline>
                </p:input>
             </p:identity>
          </p:when>
       </p:choose>

    </p:declare-step>

  But when I execute it with Calabash, I get the error "XE0001:
Unreadable port: result on s".  I guess I missed (again) something
obvious, but what?

  Best regards,

-- 
Florent Georges
http://fgeorges.org/