(ansible_distribution == 'RedHat'): 'ansible_distribution' is undefined

https://thirdparty.logs.rdoproject.org/jenkins-tripleo-quickstart-pike-rdo_trunk-baremetal-dell_fc430_envB-single_nic_vlans-58/console.txt.gz

TASK [overcloud-deploy : Use KVM for Red Hat distro] ***************************
task path: /home/rhos-ci/jenkins/workspace/tripleo-quickstart-pike-rdo_trunk-baremetal-dell_fc430_envB-single_nic_vlans/usr/local/share/ansible/roles/overcloud-deploy/tasks/pre-deploy.yml:174
Thursday 05 October 2017 21:52:38 +0000 (0:00:00.129) 0:44:18.441 ******
fatal: [undercloud]: FAILED! => {
    "failed": true,
    "msg": "The conditional check 'ansible_distribution == 'RedHat'' failed. The error was: error while evaluating conditional (ansible_distribution == 'RedHat'): 'ansible_distribution' is undefined\n\nThe error appears to have been in '/home/rhos-ci/jenkins/workspace/tripleo-quickstart-pike-rdo_trunk-baremetal-dell_fc430_envB-single_nic_vlans/usr/local/share/ansible/roles/overcloud-deploy/tasks/pre-deploy.yml': line 174, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Use KVM for Red Hat distro\n ^ here\n"
}