[racket-dev] Contract violation from custodian shutdown

It's hard to say where the bug is, but there may be some problem in the
implementation of custodians of `register-custodian-shutdown'. Is it
repeatable?

At Thu, 06 Dec 2012 16:48:37 -0700, Neil Toronto wrote:
> I just got this message on my console, I think after closing a tab, 
> which coincided with DrRacket hanging:
> 
> 
> eventspace-shutdown?: contract violation
>    expected: eventspace?
>    given: #<procedure:mpfr_free_cache>
>    context...:
>     /home/neil/plt/collects/mred/private/wx/common/queue.rkt:201:0: 
> shutdown-eventspace!
> 
> 
> It's obviously because of this code, which is near the top of 
> "math/private/bigfloat/mpfr.rkt":
> 
> 
> (define mpfr-free-cache (get-mpfr-fun 'mpfr_free_cache (_fun -> _void)))
> 
> (define mpfr-shutdown
>    (register-custodian-shutdown mpfr-free-cache (λ (free) (free))))
> 
> 
> Did I misunderstand something, or is this someone else's bug?
> 
> Neil ⊥
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