title: Could not import module frege.system.Directory (java.lang.ClassNotFoundException: frege.system.Directory)
body: <p>I tried to import System.Directory in my Frege program (In Eclipse) in order to use functions as getDirectoryContent, etc., and it writes me this error :
  Could not import module frege.system.Directory (java.lang.ClassNotFoundException: frege.system.Directory)</p>
  
  <p>What do I have to do ?</p>