RHEL 5.6 and mock for RHEL 6 x86_64?

[Chris Adams <cmadams hiwaay net>]

My build system is a VM running RHEL 5 x86_64 with the builder-rpms repo
(so I can build newer Fedora and RHEL 6 packages).  I loaded the RHEL
5.6 updates today, and now I can't build RHEL 6 x86_64 packages (it
worked up until now).  I can't even initialize the mock root; the
install of glibc fails with:

/usr/sbin/glibc_post_upgrade: While trying to execute /usr/sbin/iconvconfig.x86_64 child terminated abnormally
Non-fatal POSTIN scriptlet failure in rpm package glibc-2.12-1.7.el6_0.3.x86_64
warning: %post(glibc-2.12-1.7.el6_0.3.x86_64) scriptlet failed, exit status 115

I can still init the RHEL 6 i386 root; the problem appears to be
isolated to x86_64.  I found that if I boot back into an older kernel,
it works, so it is something about kernel-2.6.18-238.el5.x86_64.  Any
ideas?
-- 
Chris Adams <cmadams hiwaay net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.