When did you get this kind of error?

Is your camlp4 installed in the expected directory (camlp4 -where)?

If it's a manual compilation command the recommended flag is
``-I +camlp4/Camlp4Parsers''.

Excerpts from Richard Jones's message of Thu Aug 02 18:20:11 +0200 2007:
> On Thu, Aug 02, 2007 at 06:14:32PM +0200, Gabriel Kerneis wrote:
> > Le Thu, 2 Aug 2007 17:00:16 +0100, Richard Jones <rich@annexia.org> a
> > écrit :
> > > I'm getting a bunch of errors like this:
> > > 
> > > Camlp4: Uncaught exception: DynLoader.Error
> > > ("Camlp4OCamlRevisedParser.cmo", "file not found in path")
> > > 
> > > These can be solved by adding '-I `ocamlc
> > > -where`/camlp4/Camlp4Parsers' to every invocation of camlp4 commands,
> > > but I wonder why the path isn't there already.  Is this a bug?
> > 
> > -I +camlp4 doesn't work?
> 
> No.  +camlp4 seems to be on the path already, but not that
> subdirectory.
> 
> Rich.
> 

-- 
Nicolas Pouillard aka Ertai