"Unexpected restart" error

[Chinmaya Nagpal]

Hi,

Newbie here, to both this list and to Scheme. I'm trying to work through
the Structure and Interpretation of Classical Mechanics, and for the
past two days I've been trying and failing to run some Scheme code using
org-babel and geiser in Emacs. I've reduced my problem down to the
following.

In a brand-new MIT-Scheme session, if I type[1] the following code:

  (begin ;; -*- something: something -*-
    (+ 2 2))

I get the this error:

  ;Unexpected read restart on: #[textual-i/o-port 12 for console]
  ;To continue, call RESTART with an option number:
  ; (RESTART 1) => Return to read-eval-print level 1.

It took a while to reduce the problem to this, and I've tried debugging
it by going through the MIT-Scheme source code but I'm not able to get
anywhere.

I'm not sure if this is the right place to ask, or if should post in the
devel list. Any guidance on what this is/how I might find out would be
appreciated.

Best,  
Chinmaya

[1] or rather try to type, as this error shows up as soon as I press RET
at the end of the first line