Support for the ARM 64 bit CPU architecture (aarch64) was introduced in autoconf 2.69. bzflag appears to use an earlier version of autoconf, preventing its being built. This can be fixed in of three ways (In order of preference): 1. Work with upstream to migrate the package to autoconf 2.69. 2. Rerun autoconf or autoreconf in %prep or %build prior to running configure. 3. Apply the patch at http://ausil.fedorapeople.org/aarch64/bzflag/bzflag-aarch64.patch which updates config.guess and config.sub to recognize aarch64.
A fix is committed to git, but the koji build fails because of the missing automake dependency noted in bug 924938. If that bug isn't resolved soon enough I can work around it by adding perl-Carp as a bzflag build dependency.
bzflag-2.4.2-6 has been built for rawhide and f19. This RPM version provides aarch64 support by regenerating the configuration scripts -- including config.guess and config.sub -- using the current autoconf (2.69 at this time) in %prep.