silly little problem, silly little patch

[Nicolás Lichtmaier]

> Sorry, I can't fix it in confutre because the file is created from
> configure.in and a library of macro defs which are part of automake;
> a new version of automake would break it.

 If the problem is just the CDPATH variable, you may unset it at the top of
configure.in. Remember that you can type any shell script commands into
configure.in.