[plt-scheme] Using threads in Teaching Languages through teachpack

From: Wayne Iba (iba at westmont.edu)
Date: Mon Jun 5 15:02:46 EDT 2006

I posted this general issue last week but I've narrowed it down just a 
bit.  I still need your help.  The goal is to give students a teachpack 
that lets them create threads.  This simple teachpack works fine in 
"Textual" but fails in "Advanced Student" (v300 and v301).  Here is the 

(module exposethread mzscheme
  (provide thread)

and here is the error from evaluating (thread (lambda () (display "show 
this independently")))

hash-table-get: expects type <hash-table> as 1st argument, given: false; 
other arguments were: 'test-coverage-point22886

Maybe I'm missing something simple?  As I mentioned before, this works 
fine in v207. Thanks in advance,
--Wayne Iba

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