title: Eclipse link to external source path
body: <p>I have Java project that uses a JAR from another Eclipse project (open source from apache).
  For debug I need access to the source.
  I have no idea where to point the source path. Everything I tried fails.<br>
  All my sources are under <code>project/src/org/apache/...</code>.</p>
  
  <p>Nota : it used to work but I upgraded eclipse as well as my apache project and it ain't working anymore.</p>