> Maybe one of those is actually being used?
>
> Your basic argument is:
>
> (a) the make process works for normal Ocaml
> (b) you removed only unused functions from one library being linked in
>    by stubbing them out
> (c) now it crashes
>
> ==> contradiation.
>
> Clearly the most likely is that (b) is wrong :)

Perhaps, but I've tried adding a few, and can't find anything.

Anyways, how can I find out what the given bytecode instruction is?
I've added some debugging to caml_interprete() to list the how many
instructions have passed.

Here's an even simpler example of what causes my bytecode to 'crash':

external print_string: string -> unit = "my_print_string";;
let printf args = Printf.ksprintf print_string args;;
print_string "Kernel shutting down..";;

the declaration of printf above causes it to fail. comment it out, it's fine.

Jonathan