arc:try

<arc:call op="...">
  <arc:try>
    <arc:throw code="myerror" description="thedescription" details="Other Details."/>
    <arc:catch code="myerror">
      <arc:set attr="arc:ecode" value="[_code]"/>
      <arc:set attr="arc:emessage" value="[_description]: [_details]"/>
      <arc:push/>
    </arc:catch>
  </arc:try>
</arc:call>