npm run res:start fails

[mlegls]

When running npm run res:start in a freshly cloned repo, I get the following output

> [email protected] res:start
> rescript build -w

>>>> Start compiling 
rescript: [1/9] src/App.cmi
FAILED: src/App.cmi
can not handle multiple files
rescript: [2/9] src/Index.cmi
FAILED: src/Index.cmi
can not handle multiple files
rescript: [3/9] src/layouts/MainLayout.cmi
FAILED: src/layouts/MainLayout.cmi
can not handle multiple files
rescript: [4/9] src/bindings/Next.cmj
FAILED: src/bindings/Next.cmj
can not handle multiple files
FAILED: cannot make progress due to previous errors.
>>>> Finish compiling(exit: 1)

npm run dev works fine, and I've tried npm install with both node 6 and node 7. npx rescript build fails with the same output. The most similar issue I could find is https://forum.rescript-lang.org/t/error-can-not-handle-multiple-files/1368, which I don't think was ever resolved either. I'm on a Mac though (2020 M1 Macbook Air, MacOS Big Sur 11.6). From what I can tell, it seems like the failure happens every time rescript tries to generate OCaml files.