You can search for identifiers within the package.
in-package search v0.2.0
type 'a log = ('a, unit future) Logs.msgf -> unit future
val err : ?src:Logs.src -> 'a log
val warn : ?src:Logs.src -> 'a log
val info : ?src:Logs.src -> 'a log
val debug : ?src:Logs.src -> 'a log