This is client API (go to server)
Module Eliom_pervasives.​Printexc
module Printexc : sig..end
include Printexcval register_exn_printer : ((exn -> string) -> exn -> string) -> unit
module Printexc : sig..end
include Printexcval register_exn_printer : ((exn -> string) -> exn -> string) -> unit