[0] is a post from seven years ago where the poster installed ocaml using the Debian package manager rather than through opam as recommended and failed to use a

[0] is a post from seven years ago where the poster installed ocaml using the Debian package manager rather than through opam as recommended and failed to use a core library because they didn't understand the admittedly strange way Debian packages Ocaml. You probably shouldn't use Debian packages for Ocaml (nor for anything else admittedly - Debian has terrible habits regarding patching and splitting). The community actually standardized its way of compiling around Dune which is very good.