[plt-scheme] "mzc --gui-exe" on macos x

when i compile scheme modules with the '--gui-exe' option on macos X, i 
get a message that the compiler can't find MrEd executable.  see the 
following transcript:

--------snip--------
[localhost:~] js% cat hello.scm
(module hello mzscheme
   (require (lib "class.ss"))
   (require (lib "mred.ss" "mred"))

   (define frame (instantiate frame% ("hello")))
   (send frame show #t))

[localhost:~] js% /Applications/PLT/bin/mzc --gui-exe hello hello.scm
MzScheme compiler (mzc) version 200, Copyright (c) 1996-2001 PLT
make-embedding-executable: can't find MrEd executable
[localhost:~] js%
--------snip--------

on windows, this works like a charm.

what options/environment variables/magic encantations do i need to make 
this work on macos x?


jason songhurst