Warning-suppression

I attempted to use Andrew's solution from this thread to create a macro to suppress ALL warnings (getWarn only suppresses one).

However, it does not appear to have any effect on the warn builtin:

(defmacro bcmNoWarn (@rest body)
  `(let ((nullport (outfile "/dev/null")))
     (unwindProtect
      (let ((woport nullport))
        ,@body)
      (close nullport))))> (bcmNoWarn (warn "Careful!"))
*WARNING* Careful!nil