Bug to track this problem in rpm-4.3-0.10 (and 0.9.1, sadly :)
This affects ant and tomcat. I've only seen it on x86_64, but this may be because the hammers are faster than the other beehive machines and are beating them to it.
Actually, it only seems to happen on loma.devel. Other hammer boxes and other archs seem to build it just fine.
FIxed in rpm-4.3-0.22 and rpm-4.2.2-0.14 afaik.