> It's not the prefix that is screwed up. It's the libdir, which he is
> claiming is hardcoded as `${PREFIX}/lib'. On x86_64 multilib systems,
> this should almost always be `${PREFIX}/lib64'.
>
> For reference, the autoconf way to do this is by using:
>
> ./configure --prefix=/x --libdir=/x/lib64


This answers my question.
Thanks a lot :)

Juan