I do not know whether they were bugs, but I show a few things I have noticed.
1. a struct with #:transparent + a SRFI-1's circular list shows messed print-outs.
I had made a program of the Old-maid. The source is here.
This works fine, but let's say, when I wanted to see an environmental value, w, embedded in the game-eval, I noticed the display shows something strange.
;; Sorry, comments are written in Japanese.
(define (oldmaid n)
(let loop ((w (initialize n)))
;;; ここで例外処理を記述する
(with-handlers ((exn:fail:contract?
;;; 例外処理
(lambda (ext) (display "入力が不正です\n")
(loop w))))
;;; 本体
(if (game-ends? w)
(display (showResult (world-id1 w)))
;;; Read-Eval-Print loop
(begin (display w) ;; Adding this for debugging, for instance
(loop (print (world-go (input w) w))))))))

You see, the w, or the World struct has an circular list in it, and the process itself has no problem at all; however, the print shown becomes messed-up.
The existence of a circular list may affect to the printing.
You see, for instance, #0=#(struct:Card C 5) #1=(0 1 2 3 . #1#) (#0# #(struct:Card H 5)) and those are meaningless. The printing of struct is affected.
2. module seems to work incorrectly
According to module syntax, if we provided a cake.rkt file as shown bellow:
;;#lang racket
(module cake racket
(provide print-cake)
(define (print-cake n)
(show " ~a " n #\.)
(show " .-~a-. " n #\|)
(show " | ~a | " n #\space)
(show "---~a---" n #\-))
(define (show fmt n ch)
(printf fmt (make-string n ch))
(newline)))
it should be "required"; however, it does not work.

3. module having pictures gives an error.
I had made a binary-search tree like this:
#lang racket
(provide list->bst bst-search *av-list*)
(define (list->bst lst (cmp <) #:key (fn identity))
(define (loop lst cmp fn)
(if (null? lst)
'()
(let ((pivot (car (drop lst (quotient (length lst) 2)))))
(let ((left (loop (filter (lambda (x)
(cmp (fn x) (fn pivot)))
lst) cmp fn))
(right (loop (filter (lambda (x)
(cmp (fn pivot) (fn x)))
lst) cmp fn)))
(cond ((list? pivot) `(,@pivot ,left ,right))
((pair? pivot) (match-let (((cons k v) pivot))
`(,k ,v ,left ,right)))
(else `(,pivot ,left ,right)))))))
(loop (sort lst cmp #:key fn) cmp fn))
(define (bst-search v tree (cmp equal?) #:keyfn (kfn <) #:key (fn car))
(match tree
('() #f)
(`(,lvp ... ,left ,right)
(cond ((cmp v (fn lvp)) lvp)
((kfn v (fn lvp)) (bst-search v left cmp #:keyfn kfn #:key fn))
(else (bst-search v right cmp #:keyfn kfn #:key fn))))))
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The pictures are embedded in the source file.
The problem is, if you want to "require" this, the error occurs.

Thanks.