A possible bug?

gistfile1.rkt

#lang racket

(require web-server/servlet
         web-server/servlet-env)
(require pict)
(require file/convertible)
(require xml)

(define (pict->svg pict)
  (define svg-b (convert pict 'svg-bytes))
  (define svg-s (bytes->string/utf-8 svg-b))
  (string->xexpr svg-s))

(define (start req)
  (response/xexpr
   `(html
     (body
      ,(pict->svg (text (number->string 1))) "-"
      ,(pict->svg (text (number->string 4))) "-"
      ,(pict->svg (text (number->string 5)))
      ))))

(serve/servlet start)