"./pulp-planner run" fails with Undefined namespace prefix

[thom-at-redhat]

./pulp-planner run

11:12/usr/share/gems/gems/nokogiri-1.8.1/lib/nokogiri/xml/searchable.rb:198:in `evaluate': ERROR: Undefined namespace prefix: /xmlns:repomd/xmlns:data[@type="primary"]/xmlns:location (Nokogiri::XML::XPath::SyntaxError)

from /usr/share/gems/gems/nokogiri-1.8.1/lib/nokogiri/xml/searchable.rb:198:in `xpath_impl'
from /usr/share/gems/gems/nokogiri-1.8.1/lib/nokogiri/xml/searchable.rb:179:in `xpath_internal'
from /usr/share/gems/gems/nokogiri-1.8.1/lib/nokogiri/xml/searchable.rb:154:in `xpath'
from /home/tcarlin/satellite/6/pulp/pulp-planner/lib/disconnected_pulp.rb:144:in `primary'
from /home/tcarlin/satellite/6/pulp/pulp-planner/lib/disconnected_pulp.rb:188:in `initialize'
from /home/tcarlin/satellite/6/pulp/pulp-planner/lib/disconnected_pulp.rb:73:in `new'
from /home/tcarlin/satellite/6/pulp/pulp-planner/lib/disconnected_pulp.rb:73:in `block in run'
from /home/tcarlin/satellite/6/pulp/pulp-planner/lib/disconnected_pulp.rb:70:in `each'
from /home/tcarlin/satellite/6/pulp/pulp-planner/lib/disconnected_pulp.rb:70:in `run'
from ./pulp-planner:294:in `<main>'