[racket] [plt-scheme] get-uncovered-expressions always returns () ?

I'm stuck with the same issue as the email below, which is from
several months ago but didn't have any replies on the mailing list.
Was there some solution to this?
Thanks,
nadeem

On Tue, Jan 19, 2010 at 8:06 PM, John Clements
<clements at brinckerhoff.org> wrote:
> I'm having no luck in persuading the coverage-tester to work in scheme/sandbox.
>
> Specifically, I observe about this program:
>
> #lang scheme
>
> (require scheme/sandbox)
>
> (define stx-placeholder #'abc)
>
> (define to-be-evaluated
>  (datum->syntax
>   #f
>   `(module user lang/htdp-beginner
>      (require schemeunit/check)
>      (define (f x) (+ 3 x)))
>   stx-placeholder))
>
> (define evaluator
>  (parameterize ([sandbox-output 'string]
>                 [sandbox-coverage-enabled #t])
>    (make-module-evaluator
>     to-be-evaluated)))
>
> (evaluator '3)
>
> (get-uncovered-expressions evaluator #f
>                           ;#t (syntax-source stx-placeholder)
>                           )
>
> that
> a) it's about the simplest use of get-uncovered-expressions, and
> b) it's not working. Specifically, the call to get-uncovered-expressions
>  produces (), when it appears to me that it shouldn't (in that the function 'f'
>  is never called.
>
> Please let me know if I'm mistaken about either (or both!) of these observations.
>
> (FWIW, this is 4.2.3.9svn4jan2010; perhaps an update would help?)
>
> John
>
>
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>
>



-- 
Nadeem Abdul Hamid
Assistant Professor, Computer Science
Berry College
PO Box 5014
2277 Martha Berry Hwy NW
Mount Berry, GA 30149-5014
(706) 368-5632
http://cs.berry.edu/~nhamid/