[chef] Error with knife and Rackspace API v2

[Larry Wright < >]

I'm trying to bootstrap a server on Rackspace's new Openstack cloud platform, 
and I get an error when I run the knife command:

$ knife rackspace server create -I 125 -f 4 -E development -r 
'role[hourly_build_minimal]' --server-name hourlybuildtest3.example.com 
--node-name hourlybuildtest3.example.com 

ERROR: Fog::Compute::RackspaceV2::BadRequest: 
Fog::Compute::RackspaceV2::BadRequest

Relevant versions of things:
fog (1.7.0)
knife-rackspace (0.6.2)


Anyone else seen this?