[racket] Handin Server + PLAI problem [and 1 more messages] [and 2 more messages]

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Fri Jan 20 11:26:52 EST 2012

This didn't work for me with the following submission (in version 5.2):

#lang plai
(halt-on-errors #t)

On Sun, Jan 15, 2012 at 6:45 PM, Eli Barzilay <eli at barzilay.org> wrote:
> 50 minutes ago, Robby Findler wrote:
>> I'm not sure either (this is certainly not the only contract that's
>> checked during the execution of PLAI programs, but maybe it's the
>> only provide/contract one?), but once I disabled that, my sample
>> solution for the next exercise went through.
>> It would be good to know how to get a better short-term solution,
>> however (like making a more relaxed sandbox that allows exists
>> queries in the handin server).
> This is "easy":
>  (parameterize ([sandbox-path-permissions '([exists "/"])])
>    ...make the evaluator...)
> except that I think that in the context of the handin server you don't
> create it directly.  It's probably doable by making the change
> globally, via a hook:
> Create a "hook.rkt" file with:
>  #lang racket/base
>  (provide hook)
>  (require racket/sandbox)
>  (define (hook what session alist)
>    (when (eq? what 'server-start)
>      (sandbox-path-permissions '([exists "/"]))))
> Then wire it in with an entry in the config file that says:
>  (hook-file "hook.rkt")
> Or, if you already have a hook, then add the parameter change to it.
> --
>          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
>                    http://barzilay.org/                   Maze is Life!

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