Using an ocamlfind installation of sexplib

Install type-conv and sexplib according to the instructions given at ocaml.info using ocamlfind.

Define the following in your plugin :

let ocamlfind_query pkg =
  let cmd = Printf.sprintf "ocamlfind query %s" (Filename.quote pkg) in
  My_unix.run_and_open cmd (fun ic ->
      Log.dprintf 5 "Getting Ocaml directory from command %s" cmd;
      input_line ic
    )

Then, in After_rules:

let sexplib_dir = ocamlfind_query "sexplib" in
  let type_conv_dir = ocamlfind_query "type-conv" in
  ocaml_lib ~extern:true ~dir:sexplib_dir "sexplib";
  flag ["ocaml"; "pp"; "use_sexplib.syntax"]
  & S[A"-I"; A type_conv_dir; A"-I"; A sexplib_dir;
      A"pa_type_conv.cmo"; A"pa_sexp_conv.cmo"]

Ensure that each .ml file that will use the sexplib syntax (type foo = ... with sexp) is tagged with camlp4o and use_sexplib.syntax, as in:

<**/*.ml>: camlp4o, use_sexplib.syntax

Do not forget to add

open Sexplib
open Sexp
TYPE_CONV_PATH "Foo"

to your modules.