Source : Free On-Line Dictionary of Computing

casting the runes
     
         What a {guru} does when you ask him or her to run a
        particular program because it never works for anyone else;
        especially used when nobody can ever see what the guru is
        doing different from what J. Random Luser does.
     
        Compare {incantation}, {runes}, {examining the entrails}; also
        see the {AI koan} about Tom Knight.
     
        (1997-12-26)