> Try to see the reverse of the coin. For distros like
> gentoo, packages are 
> splitted. So, if everything are enabled by default, ebuilds
> should disable 
> _every_ unneeded stuff, for each package.

That is how the process should work. Let the downstream packagers handle what they want. As upstream providers we need to ensure everything works.

> cmake should not try to detect things at any cost.
> Everywhere is possible, is 
> used pkgconfig.

So basically we might still need to use the -DINCLUDE_DIRECTORIES option should the pkgconfig file be incorrect.

Will the build halt when I specify -DWITH_SPEEX, don't use -DINCLUDE_DIRECTORIES, and cmake can't find the speex header files?

Darrell