If I have my project set up like this:

├── file.ml

├── plugins

│ └── puz

│ ├── puz_bin.ml

│ ├── puz_match.ml

│ ├── puz.ml

│ ├── puz_plugin.mllib

│ ├── puz_types.ml

│ └── puz_utils.ml

└── _tags

$ cat plugins/puz/puz_plugin.mllib

Puz Puz_bin Puz_match

This works:

$ ocamlbuild -use-ocamlfind plugins/puz/puz_plugin.cmxa

Finished, 22 targets (3 cached) in 00:00:03.

My _tags file:

------------------------------------------------

$ cat _tags

true: thread,debug

true: package(core_kernel)

"plugins/puz": include

<gui.*>: package(labltk)

<**/puz.*>: package(unix), package(str), package(core_kernel), package(bitstring), package(mikmatch_pcre)

<**/*_bin.*>: package(bitstring.syntax), syntax(bitstring)

<**/*_match.*>: package(mikmatch_pcre), syntax(camlp4o)

------------------------------------------------

But I can't figure out how to use this library in my main program. This is a minimal example of what I'm trying to do, not working of course:

$ cat file.ml

open Core_kernel.Std

let read fname =

let data = In_channel.read_all fname in

Puz_plugin.read data

$ ocamlbuild -use-ocamlfind file.native

+ ocamlfind ocamlc -c -g -thread -package core_kernel -I plugins/puz -o file.cmo file.ml

File "file.ml", line 5, characters 2-17:

Error: Unbound module Puz_plugin

martin