Extending Comparable.Make with ppx_jsonaf_conv compatible serializers

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I need to do the following:

open Core

module Foo : sig
  type t = string [@@deriving compare, sexp, jsonaf]

  include Comparable.S with type t := t
end = struct
  module T = struct
    type t = string [@@deriving compare, sexp, jsonaf]
  end

  include T
  include Comparable.Make (T)
end

module Bar = struct
  type t = { foo : int Foo.Map.t } [@@deriving compare, sexp, jsonaf]
end

but this fails with:

File "test.ml", line 15, characters 23-32:
15 |   type t = { foo : int Foo.Map.t } [@@deriving compare, sexp, jsonaf]
                            ^^^^^^^^^
Error: Unbound value Foo.Map.t_of_jsonaf

I can provide the serializers easily enough with this module:

module Map_with_jsonaf : sig
  include Map.S with type Key.t = Foo.t

  val t_of_jsonaf : (Jsonaf.t -> 'a) -> Jsonaf.t -> 'a t
  val jsonaf_of_t : ('a -> Jsonaf.t) -> 'a t -> Jsonaf.t
end = struct
  include Map.Make (Foo)

  module Assoc_list = struct
    type 'a t = (string * 'a) list [@@deriving jsonaf]
  end

  let t_of_jsonaf (a_of_json : Jsonaf.t -> 'a) (json : Jsonaf.t) : 'a t =
    Assoc_list.t_of_jsonaf a_of_json json |> of_alist_exn
  ;;

  let jsonaf_of_t (a_to_json : 'a -> Jsonaf.t) (t : 'a t) : Jsonaf.t =
    t |> Map.to_alist |> Assoc_list.jsonaf_of_t a_to_json
  ;;
end

but I need this Map module to extend the Comparable.S signature. In the signature of Foo I want to do something like include Comparable.S with Map := Map_with_jsonaf. I’ve tried various permutations but can’t get this to work. Is it possible?