When using quantum-openvswitch-agent you need the ovs-vsctl binary provided by net-misc/openvswitch. Maybe a use flag to toggle OVS (instead of linux bridge) could be useful here? Reproducible: Always
Please do not CC maintainers when you cannot assign bugs.
I asked him to do so :(
fixed in quantum-2013.1.2-r1 and in quantum-2012.2.4-r1