Roi Martin <jroi.martin@gmail.com> writes:

>> I tried with:
>>
>> #+begin_src scheme :scheme chez
>>   (+ 3 4)
>> #+end_src
>>
>> and also with ':scheme racket'.
>>
>> Unfortunately, it does not seem to work when exporting the document.
>>
>> Thanks for your help!
>>
>>         Roi

I've installed chez and racket.  Indeed, the argument :session
if half-ignored.

I've attached a quick ugly hack; with that change, it is now working
for me.

    #+begin_src scheme :scheme racket
      (banner)
    #+end_src

    #+RESULTS:
    : Welcome to Racket v8.14 [cs].\n

    (setq-default geiser-chez-binary "chezscheme")
    #+begin_src scheme :scheme chez 
      (scheme-version)
    #+end_src

    #+RESULTS:
    : Chez Scheme Version 10.0.0

Could you try it?

Bruno