There is a Scheme testing framework by Arthur A. Gleckler, which was developed before SRFI-64, but published only in 2020s.

https://srfi-email.schemers.org/srfi-discuss/msg/15037945/

1. It's very close to suitbl testing library and SRFI-269 in spirit.
2. It has a very neat property of saving resumable continuations on failure, so you can explore the problem in recursive REPL having all the local scope available.

#scheme #guile #srfi #testing