[racket] Trouble using make-base-eval

I was just dusting off old notes I have written in scribble that used to
work, but now I get an error, which I've boiled down to the following
example:

$ cat try.scrbl
#lang scribble/manual
@(require scribble/eval)
@(define some-eval
   (make-base-eval #:lang 'racket))

$ scribble --pdf try.scrbl
namespace-attach-module: a different module with the same name is
already in the destination namespace
  module name:
"/Users/dvanhorn/git/racket/racket/collects/racket/pretty.rkt"
  context...:

/Users/dvanhorn/git/racket/pkgs/scribble-pkgs/scribble-lib/scribble/eval.rkt:342:4

/Users/dvanhorn/git/racket/racket/collects/racket/private/more-scheme.rkt:147:2:
call-with-break-parameterization
   /Users/dvanhorn/git/racket/pkgs/sandbox-lib/racket/sandbox.rkt:833:5:
loop

This is on 6.0.0.2--2014-02-04.

Is this something that should work, or have I done something wrong.  Is
there some way for me to work around the pretty.rkt issue?

Thanks,
David