Packages for AUR.
It's reccomended to build in a clean chroot:
https://wiki.archlinux.org/index.php/DeveloperWiki:Building_in_a_Clean_Chroot
This is for building 32 bit packages on 64 bit systems:
https://wiki.archlinux.org/index.php/Building_32-bit_packages_on_a_64-bit_system