Hello,

I am implementing an integration with dune (see ocaml/dune#1201).

If I understand it correctly, at the moment, the configuration is read in cascade from the closest .ocamlformat all the way up until a global .ocamlformat file.

In the context of dune, this can cause reproducibility problems, because in a dune project with no .ocamlformat file (or with a partial one), running ocamlformat on a file will read each developer's global configuration file, and will cause different results.

I'm not sure about the best technical solution, but a --root configuration option that never reads files above a particular directory seems enough. This option would also disable reading the global configuration file and from the environment as well.

What do you think about this?

Thanks!