% grep DEPEND linux-headers-2.6.22-r2.ebuild DEPEND="dev-util/unifdef" RDEPEND="" % http://overlays.gentoo.org/proj/alt/browser/trunk/prefix-overlay/dev-util - No unifdef package. Please add the package to the tree. I ran eapify on the ebuild and emerged it just fine on a x86 system.
unifdef is in the tree for a while now.