Don't set rootpw on build* machines, it's set later in their playbooks

roles/base/tasks/main.yml

@@ -30,6 +30,7 @@
   user: name=root password={{ rootpw }} state=present
   tags:
   - rootpw
+  when: not inventory_hostname.startswith('build')
 
 - name: add ansible root key 
   authorized_key: user=root key="{{ item }}"