(While it seems that the project isn’t active) I’m interested not because of the Rust part but because of the more independent part, with plans to implement conditions and restarts [0].
I’ve mentioned a few days ago [1] about the lack of a clean and consistent lisp (in the development sense, not in the core-language-is-tiny sense) with a CL-like REPL-driven development workflow: maybe Clojure with conditions and restarts can be part of the picture?
(In Common Lisp, restarts and conditions are a major part of the REPL as it allows the REPL to have a mechanism to catch error conditions and allows the user to resume execution appropriately, after the user debugs and fixes errors.)
It does allow errors to be caught by the Repl and choose how to handle them.
Honestly though, I haven't found the interactive restarts at the REPL useful. It's way faster to just re-evaluate the code again.
Maybe in CL they are more useful because the language is full of mutation? I can't say, I've only ever done Clojure and Emacs Lisp, but in Clojure I tried that library, and found picking options at the REPL to handle the condition was more laborious than just fixing whatever or adding a catch and pressing Ctrl+Enter again.