Nic::Base.uniq_with_hosts fails if host is nil
In the staypuft plugin, we've added a VipNic subclass of Nic::Managed to manage virtual IPs for a deployment. In this class, we've overridden require_host? to return 'false' since these will not be associated with a particular host.
The one thing that isn't working for us here is that the uniq_with_hosts validation fails since it's calling host.mac. I will submit a PR which adds a check to see if the host reference is set. If the host is nil, the result is the same as if the host's value is not in conflict -- the validation continues to the elsif in the loop to determine if the value is already in use on another host.