Multiarch question

[Michael Wild <themiwi@users.sourceforge.net>]

Hi all

I have a question concerning multiarch [1,2]. From what I read it is
conceivable to have something like this on a system:

/usr/{lib,include}/i386-linux-gnu
/usr/{lib,include}/x86_64-linux-gnu
/usr/{lib,include}/x86_64-kfreebsd-gnu
/usr/{lib,include}/sparc64-linux-gnu

Particularly, the case where both linux and kfreebsd directories are
present is of interest. How would one tell gcc to use the foreign kernel?

The background of this question is that at the moment Clang is
completely broken w.r.t. multiarch and I'm looking into fixing it.

Thanks for any hints

Michael

[1] http://wiki.debian.org/Multiarch
[2] https://wiki.ubuntu.com/MultiarchSpec)