Tests p:unarchive: It is a dynamic error, if unarchived document does not have a valid base URI.
Test ab-unarchive-018.xml is expected to fail with error code err:XD0064 [XProc, Core steps].
<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" name="pipeline" version="3.0">
   <p:output port="result">
   <p:archive> <!-- archive does not have base uri -->
      <p:with-input>
         <p:inline>
            <doc/>
         </p:inline>
      </p:with-input>
   </p:archive>
   <p:unarchive relative-to="%gg">
</p:declare-step>
Added option "relative-to" to p:archive-manifest
Additional tests for p:unarchive