For those who want a Chez REPL which automatically uses the runtime, this appears to work:

#!/usr/bin/env scheme --program
(import (only (chezscheme)
              new-cafe
              lambda
              eval
              interaction-environment)
        (control-features))

(new-cafe (lambda (x) (run (lambda () (eval x (interaction-environment))))))

Daphne

> On 8 Jan 2025, at 11:38, Daphne Preston-Kendal <xxxxxx@nonceword.org> wrote:
>
> Ah, thanks!
>
> This should really be noted in the ‘Sample Implementation’ section of the specification.
>
>
> Daphne
>
>> On 8 Jan 2025, at 11:27, Shiro Kawai <xxxxxx@gmail.com> wrote:
>>
>> The SRFI needs to intercept the evaluation mechanism, so it's not supposed to run as is in the bare REPL.
>>
>> See https://srfi-email.schemers.org/srfi-226/msg/21181936/
>>
>>
>> On Tue, Jan 7, 2025 at 11:59 PM Daphne Preston-Kendal <xxxxxx@nonceword.org> wrote:
>> See the subject line. Alas, I can’t offer much more help than this REPL transcript:
>>
>> Chez Scheme Version 10.1.0
>> Copyright 1984-2024 Cisco Systems, Inc.
>>
>>> (import (control-features))
>>> (define my-tag (make-continuation-prompt-tag 'foo))
>>> (continuation-prompt-available? my-tag)
>> Exception in dynamic-environment-metacontinuation: #f is not of type #<record type dynamic-environment>
>> Type (debug) to enter the debugger.
>>> (call-with-continuation-prompt (lambda () (continuation-prompt-available? my-t
>> ag)) my-tag)
>> Exception in dynamic-environment-marks: #f is not of type #<record type dynamic-environment>
>> Type (debug) to enter the debugger.
>>> (with-continuation-mark 'magic #t (current-continuation-marks))
>> Exception: failed assertion continuation at line 436, char 10 of control-features.sls
>> Type (debug) to enter the debugger.
>>
>>
>> Daphne
>>
>