How do you get that to work?

  #lang racket
  (read-syntax-accept-graph #t)
  (let ((a '#0=(0 . #0#)))
    (display (car a)))

...which of course doesn't work, because `(read-syntax-accept-graph)` is a run-time thing, and the circular-list structure is a `read`-time thing.

I couldn't figure it out with this either:

https://stackoverflow.com/questions/51942188/read-syntax-for...

...just to make sure I wasn't going crazy, this:

  (let ((a '#0=(0 . #0#)))
    (display (car a)))

...does work as expected with this online scheme interpreter:

https://www.jdoodle.com/execute-scheme-online