Unable to add a cookbook recipe for "Eio" (might affect all ocaml-5-only packages?)

[richardhuxton]

While writing some cookbook recipes for promises, I tried to add one for "Eio" and the website rebuild failed.

It appears to be an issue at the yaml header / packages level. My first guess is that this is because there is no "eio" package for ocaml 4.14?

Here is a sample recipe that fails:

---
packages:
- name: eio
  tested_version: 1.1
  used_libraries:
  - eio
discussion: Dummy recipe
---

let () =
  print_endline "Hello world"

I don't know of a way to search for other ocaml-5-only packages so can't test my hypothesis.