This might be an embarrassingly simple question. How are people building multi-arch library packages on CentOS 7? On older releases one could "mock -r epel-6-i386" and "mock -r epel-6-x86_64" to build a library twice. With no 32-bit release, there's no epel-7-i386 target for mock. Specifying --target=i386 or --arch-i386 both fail. Do we have to set up the environment manually and rpm --rebuild inside the mock root?