On 30 Nov 2009, Daniel P. Berrange stated:
What's confusing it here is that you've not connected a real
physical
network interface to the bridge - it is expecting to find a ethernet
device enslaved, and instead finds 'dummy0'.
I'm not bothering with dummy0 anymore: my bridges are empty save for VM
network interfaces (connected to the real network via ordinary routing).
Let's see if this works with the virt-manager/libvirt fix Cole
mentioned...