We have a string ip=/sbin/ip on the 26th line of /sbin/dhclient-script which is incorrect cause iproute2 install ip to /bin/ip. And ${ip} is used only in "DHCPv6 Handlers" block which make net-misc/dhcp obviously RDEPEND on iproute2 only when using USE=ipv6.
should be all set now in the tree; thanks for the report! Commit message: Fix path to iproute2 ip program http://sources.gentoo.org/net-misc/dhcp/dhcp-4.2.5_p1-r1.ebuild?rev=1.1 http://sources.gentoo.org/net-misc/dhcp/files/dhcp-4.2.5-iproute2-path.patch?rev=1.1