You can also define a printer for the exception Unix_error, once and for
all.

let _ =
  Printexc.register_printer (fun exn ->
    match exn with
      Unix.Unix_error (error, s1, s2) ->
        Some (Printf.sprintf "Unix_error(%s, %s, %s)"
(Unix.error_message error) s1 s2)
    | _ -> None)
;;

It would probably be a good idea to include this code directly in the
Unix module of the distribution, no ?
--Fabrice

On 03/08/2011 03:36 PM, Gerd Stolpmann wrote:
> Am Dienstag, den 08.03.2011, 13:17 +1100 schrieb Arlen Cuss:
> 
>> Exception Unix.Unix_error(31, "write", "") occurred
>> Exception Unix.Unix_error(56, "write", "") occurred
>>
>> Both are occurring with the same reported backtrace; the former is Unix
>> error EMLINK (too many links), the latter EISCONN (socket is connected);
>> the strange thing is that *neither* of these errors should be throwable
>> on a write() call!
> 
> That's not quite correct.
> 
> Error 31 is EPIPE. Error 56 is ECONNRESET. You can easily find out by
> typing in the toploop:
> 
> # (Obj.magic 31: Unix.error);;
> - : Unix.error = Unix.EPIPE
> # (Obj.magic 56: Unix.error);;
> - : Unix.error = Unix.ECONNRESET
> 
> The error numbers are not the official Unix ones, but something that
> ocaml uses internally.
> 
> Gerd
> 
> 
>>
>> I've ensured I'm correctly compiling with debug info, so I'm a bit lost.
>> I can only assume a sprintf or similar call somewhere is going haywire.
>>
>> Anyone seen anything like this before?
>>
>> Best,
>> Arlen
>>
>>
> 
>