dev-tcltk/thread/thread-2.6.1.ebuild uses aclocal and autoconf, but has no dependency to sys-devel/automake-wrapper or sys-devel/autoconf-wrapper.
These packages are part of the base profile, so not really necessary. But it's not my beer to resolve the bug and in future we may depend on distict autoconf/make versions.
i install my system: emerge -e system via USE-flags, there's dev-tcltk/thread to install. but automake/conf aren't installed. there's no reason to don't depend on automake/conf.
This should use autotools.eclass
Fixed in CVS