;; mkfifo ./bar.sock

(call-with-new-thread
 (lambda ()
   (do ()
       (#f)
     (sleep 2)
     (display "foo\n")))
 (lambda () ()))

(define (block-on-pipe)
  (let ((port (open-file  "./bar.sock" "r")))
    (display port)
    (read-char port)))

(block-on-pipe)