Dear camlers,

I'm desperately stuck with the following issue: I fail to compile a program
using a module, but have no problem using the module in question in the
toplevel.

Here is how I use it in the toplevel

$ ocaml
        Objective Caml version 3.12.1

# #directory
"/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R";;
# #load "/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R/
R_math.cma";;
# Rmath.pow;;
- : float -> float -> float = <fun>


Now with the following program:
$ cat test.ml
let x = Rmath.pow 2.

I try to compile with the options corresponding to the toplevel directives:

$ ocamlc -o rmath -I
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R/R_math.cma
test.ml
File "test.ml", line 1, characters 8-17:
Error: Unbound module Rmath

I'm missing something obvious, but I can't see what. Does it remind someone
of something?

Cheers,
  Philippe.

PS There should be nothing fancy in my installation:

$ which ocaml
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/bin/ocaml
$ which ocamlc
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/bin/ocamlc
$ head -n 1 /home/pveber/usr/ocamlbrew/ocaml-3.12.1/bin/ocaml
#!/home/pveber/usr/ocamlbrew/ocaml-3.12.1/bin/ocamlrun

PS2 I have no compilation problem with other modules/libraries, as shown by
the following session. I encounter (and solve) all usual compilation
errors, the way I'm used to.

$ cat test.ml
let _ = R.init
$ ocamlc -o test  test.ml
File "rmath.ml", line 1, characters 8-14:
Error: Unbound module R
$ ocamlc -o rmath -I
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R rmath.ml
File "rmath.ml", line 1, characters 0-1:
Error: Error while linking rmath.cmo:
Reference to undefined global `R'
$ ocamlc -o rmath -I
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R R.cma rmath.ml
File "rmath.ml", line 1, characters 0-1:
Error: Error while linking
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R/R.cma(Initialisation):
Reference to undefined global `Unix'
$ ocamlc -o rmath -I
/home/pveber/usr/ocamlbrew/ocaml-3.12.1/lib/ocaml/site-lib/R unix.cma R.cma
rmath.ml
$./rmath [...]