I've tried looking around but finding detailed information on multilib is a challenge. I understand what it is for and how it works but what I can't figure out is what impact it has later on when I'm building say, GTK? If I have a multilib glibc and I build another library will it automatically build both 32bit and 64bit libs or do I have to specify? Do I specify the different /libXX paths when building glibc and then it's automagic from there or do I need to specify at configure-time for each app I build?

Any info or links would be very much appreciated on this