This had one minor issue. It tried to call libtoolize which doesn't exist on Mac OS X. However, there *is* a /usr/bin/glibtoolize. When I forced it to use that everything compiled and installed cleanly.
Hmm, I just noticed that /etc/make.profile/profile.bashrc has alias libtool=glibtool alias libtoolize=glibtoolize alias sed=gsed So it looks like this issue was already anticipated. Is this a bug in the ebuild, or perhaps a bug in my environment? (Maybe I needed to manually update /etc/profile after upgrading to a new portage?)
Although this bug in general has been fixed, this was a special case because the ebuild was running libtoolize inside of a new shell. This lost the aliases, which prevented the emerge. Fixed in CVS
Closing out bugs that've been resolved for a while now...
