Hi,OCaml 5.1.0 has just been released, and a version 4.14.2 will soon be released. Current version in unstable is 4.13.1.
I played a bit with opam-debian-switch, and it turns out that (at least) 35 packages are broken (at the moment) with OCaml 5.1.0 whereas only 1 seems broken with 4.14.1.
Therefore, I am planning to migrate to 4.14.x first. Cheers, -- Stéphane