Bug in system?

[Keith Wright]

 > (define x (with-output-to-string (lambda()(display  "joy"))))
 > x
  $1 = "joy"

This is as expected.

 > (define y (with-output-to-string (lambda()(system "date"))))
  Tue Nov  6 21:42:41 EST 2012
 > y
  $2 = ""

The stdout of the system call does not go into the string,
why not?

-- 
     -- Keith Wright  <address@hidden>

Programmer in Chief, Free Computer Shop <http://www.free-comp-shop.com>
         ---  Food, Shelter, Source code.  ---