Holy crap!

gistfile1.txt

TASK: [Rsync local repo to server] ******************************************** 
failed: [192.168.1.54] => {"failed": true, "parsed": false}
invalid output was: [sudo via ansible, key=lwtfdjeriloittrxzexhobtnxsxiiclm] password: 

From the entirely innocent:

-
  name: Deploy rack application
  hosts: rack-servers
  tags: deploy
  sudo: yes
  sudo_user: rack
  vars:
    release: "{{ hostvars['localhost']['timestamp'] }}"
    release_path: /srv/rack/releases/{{release}}
    current_path: /srv/rack/current
    rsync_user: "{% if ansible_ssh_user is defined %}{{ ansible_ssh_user }}{% else %}root{% endif %}"
    rsync_host: "{% if ansible_ssh_host is defined %}{{ ansible_ssh_host }}{% else %}{{inventory_hostname}}{% endif %}"
    rsync_port: "{% if ansible_ssh_port is defined %}:{{ ansible_ssh_port }}{% else %}{% endif %}"
  tasks:
    ...
    -
      name: Rsync local repo to server
      local_action: command rsync -a --delete {{rsync}}/ --rsync-path="/usr/bin/sudo /usr/bin/rsync" {rsync_user}}@{{rsync_host}}{{rsync_port}}:{{release_path}}/
      when: rsync is defined
    ...