Pre-processor sub-process

[Matthieu Dubuget <matthieu.dubuget@gmail.com>]

Hello,

I'm trying to have bin-prot compiled with mingw version of OCaml with
the original OCamlMakefile.

This fails on my computer.

I reproduced the problem here:

On linux, there is no problem:
$ uname
Linux
$ echo $BIN_PROT_CPP
cpp
$ echo $pp
$BIN_PROT_CPP $ARCH_FLAGS
$ ocamlc -c -verbose -pp "echo $pp && $pp" write_ml.ml
+ echo $BIN_PROT_CPP $ARCH_FLAGS && $BIN_PROT_CPP $ARCH_FLAGS
'write_ml.ml' > /tmp/camlppf6e35a
cpp
File "write_ml.ml", line 33, characters 0-11:
Error: Unbound module Common

Ok. If I cat /tmp/camlppf6e35a, I can check that write_ml.ml was
actually pre-processed by cpp.

On cygwin:
$ uname
CYGWIN_NT-5.1
$ echo $BIN_PROT_CPP
cpp
$ echo $pp
$BIN_PROT_CPP $ARCH_FLAGS
$ ocamlc -c -verbose -pp "echo $pp && $pp" write_ml.ml
+ echo $BIN_PROT_CPP $ARCH_FLAGS && $BIN_PROT_CPP $ARCH_FLAGS
"write_ml.ml" > c:\DOCUME~1\matt\LOCALS~1\Temp\camlpp8a6978
$BIN_PROT_CPP $ARCH_FLAGS
'$BIN_PROT_CPP' n'est pas reconnu en tant que commande interne
ou externe, un programme excutable ou un fichier de commandes.
File "write_ml.ml", line 1, characters 0-1:
Error: Preprocessor error

It seems that when the pre-processor is called, the environment is not
given to the sub-process?

Can anybody reproduce this problem (or better: provide a solution), or
did I something bad?

P.S. Both tests are with a Godi installed 3.11.1 ocaml.

Thanks

Matt