Unbound modules using corebuild

[riseremi]

Thank you for the plugin!

I'm using corebuild (comes with core package by Jane Street) to build my project. My project structure is:

hello.ml
io.ml

And my hello.ml is:

(* 'Unbound module Core' was fixed by PKG Core *)
open Core;;

(* Cannot fix 'Unbound module Io' here *)
print_endline (Io.get_file_content "input.txt")

Io is auto-imported by corebuild, I do not #use or open it. How can I tell linter that this module is actually exists?

I tried PKG Io and B ./ in my .merlin file, but it doesn't help.