yum grouplist not working with channel created with spacewalk-create-channel

Issue

• When creating a ("freezed") channel with spacewalk-create-channel on the Satellite server, no group data seems to be created.

• The commands yum grouplist/groupinstall/groupinfo does not work on a client subscribing to such a channel.

  [root@ ~]# yum grouplist
  Loaded plugins: product-id, rhnplugin, security, subscription-manager
  Updating Red Hat repositories.
  Setting up Group Process
  Error: No group data available for configured repositories