You can search for identifiers within the package.
in-package search v0.2.0
val debug_active : bool Stdlib.ref
val debug : string -> unit
val warn : string -> string -> unit
val error : string -> string -> 'a
val print_timeout : unit -> 'a
val print_error : Unix.error -> unit
val dns_port : int
val dig : 'a -> int option -> Dns.Packet.q_class -> Dns.Packet.q_type -> string list -> unit Lwt.t
val t : unit Lwt.t