I have used Racket on the RP400. Check https://download.racket-lang.org/ https://download.racket-lang.org/ and get "Unix Source + built packages". Most likey

I have used Racket on the RP400. Check https://download.racket-lang.org/ https://download.racket-lang.org/ and get "Unix Source + built packages". Most likey it is your distribution that are missing the latest Racket version.