On Mon, Nov 29, 2010 at 09:52:20PM +0100, Sylvain Le Gall wrote:

> > There should be three variants: pkg-config, OS-based userspace policy 
> > (/usr/include vs. /usr/local/include) and user-defined one.
> > 
> 
> I think the pkg-config is the starting point, it also defines the prefix
> of the setup.data variable that we will use.

> For you OS-based detection, I can propose a header(XXX), lib(XXX). This
> will be cumulative (i.e. you can define several header and lib).
> 
> Example:
> BuildDepends: 
>   freetype2(pkg-config, header(freetype/freetype.h), lib(freetype), >= 2.0.4),
>   oUnit
> 
> The headers and libs fields are extra methods. If you define
> them, we will try to find a set of -Idirs that help to find the
> matching headers or a -Ldirs to find the matching libs. 
> 
> We will only do a detection using Sys.file_exists (i.e. don't try to
> link or anything similar). 
> 
> The detection method start with pkg-config and if it fails goes to
> headers/libs.

Excellent. I agree. I hope that default dirs for searching using 
Filename.exists will be defined somewhere not especaiily deeply.

[..]

ermine