[racket] Problems using Sandbox and Scribble

I should have guessed that you'd get that error. It's a bug in v6.1.1
that has been fixed in the development version.

Is using a development snapshot an option in your case?

  http://www.cs.utah.edu/plt/snapshots/


Otherwise, a possible workaround is to add each module with that error
to `sandbox-namespace-spec`:

   (parameterize ([sandbox-namespace-specs
                   (append (sandbox-namespace-specs)
                            '(scribble/manual scribble/racket
                              racket/stxparam-exptime))])
         ....)


At Wed, 28 Jan 2015 10:56:38 -0700, Lucas Paul wrote:
> Thanks for that, Matthew. Unfortunately, when I try that, I get a new error:
> 
> namespace-attach-module: a different instance of the same module is
> already in the destination namespace
>   module name: "/usr/share/racket/collects/racket/stxparam-exptime.rkt"
> 
> On Tue, Jan 27, 2015 at 2:03 PM, Matthew Flatt <mflatt at cs.utah.edu> wrote:
> > The `#:requires` option of `make-evaluator` requires the named modules
> > in the sandbox's namespace, but the module instances are distinct from
> > any instances in the original namespace.
> >
> > To attach the original namespace's instances to the sandbox's
> > namespace, use the `sandbox-namespace-specs` parameter:
> >
> >  (define safe-eval
> >    (parameterize ([sandbox-namespace-specs
> >                    (append (sandbox-namespace-specs)
> >                            '(scribble/manual scribble/racket))])
> >      (make-evaluator 'racket/base
> >                      #:requires '(scribble/manual scribble/racket))))
> >
> > At Tue, 27 Jan 2015 13:22:01 -0700, Lucas Paul wrote:
> >> Hi.
> >>
> >> I want to evaluate some scribble things (in a sandbox) and then
> >> combine them with other scribble things I already have lying around.
> >> But I'm running into a problem.
> >>
> >> If I, for example, make a nicely formatted (racket) code block in a
> >> sandbox, and then put it in a (para) outside of that sandbox, the
> >> world explodes. Here is a minimal example:
> >>
> >> #lang racket
> >>
> >> (require racket/sandbox
> >>          scribble/manual)
> >>
> >> (define safe-eval
> >>   (make-evaluator 'racket/base #:requires '(scribble/manual 
> scribble/racket)))
> >>
> >> (pretty-print (racket foo))  ; Gives one output
> >> (pretty-print (safe-eval '(racket foo)))  ; Gives a slightly DIFFERENT 
> output
> >>
> >> (para (racket foo))  ; Finishes happily
> >> (para (safe-eval '(racket foo)))  ; Error
> >>
> >> ; end
> >>
> >> This is the error I get:
> >>
> >> para: contract violation
> >>   expected: pre-content?
> >>   given: (cached-element (style "RktSym" (list 'tt-chars (css-addition
> >> '(collects #"scribble" #"racket.css")) (tex-addition '(collects
> >> #"scribble" #"racket.tex")))) "foo" (vector (style "RktSym" (list
> >> 'tt-chars (css-addition '(collects #"scribble" #"racket...
> >>   in: an element of
> >>       the rest argument of
> >>       (->*
> >>        ()
> >>        (#:style (or/c style? string? symbol? #f))
> >>        #:rest
> >>        (listof pre-content?)
> >>        paragraph?)
> >>   contract from:
> >>       <pkgs>/scribble-lib/scribble/base.rkt
> >>   blaming: anonymous-module
> >>    (assuming the contract is correct)
> >>   at: <pkgs>/scribble-lib/scribble/base.rkt:337.2
> >>
> >> What is going on? Why does the same piece of code have two different
> >> results depending on where it's executing? And most importantly, is
> >> there a way for me to get this to work the way I /want/?
> >>
> >> - Lucas Paul
> >> ____________________
> >>   Racket Users list:
> >>   http://lists.racket-lang.org/users