Get files error

Good day everyone. I do not understand why can not execute playbook and ask for your help.

Playbook:

--- 
- 
  hosts: web
  sudo: true
  tasks: 
    - 
      name: "Download UI"
      command: wget --auth-no-challenge --http-user={{ username }} --http-password={{ password }} {{ package-ui }} chdir=/tmp/
  vars: 
    package-ui: "https://hudson.example.com/job/23/artifact/*zip*/archive.zip"
    username: username
    password: password

Conclusion execution playbook:

linux-31ne:~/tmp/ansible/playbook> ansible-playbook download.xml

PLAY [web] ********************************************************** 

GATHERING FACTS *************************************************************** 
ok: [web]

TASK: [Download UI] *********************************************************** 
fatal: [web] => unable to look up a name or access an attribute in template string

FATAL: all hosts have already failed -- aborting

PLAY RECAP ******************************************************************** 
           to retry, use: --limit @/home/username/download.xml.retry

web              : ok=1    changed=0    unreachable=1    failed=0

What a mistake and what it means?