title: ansible *when* say : "error while evaluating conditional"
body: <p>I try to do something like that:</p>
  
  <p>I have this playbook</p>
  
  <pre><code>---
  - hosts: all 
    vars:
      user: myuser
      venv_name: venv
      only_deploy_code: "yes"
    roles:
      - my_venv
  </code></pre>
  
  <p>In roles/my_venv/tasks/main.yml::</p>
  
  <pre><code>---
  - name: pip Install packages into virtualenv
    pip: name={{ item }} virtualenv="{{ home }}/{{ venv_name }}" virtualenv_site_packages="yes"
    with_items:
      - PyYAML
      - numexpr
    sudo_user: "{{ user }}"
    sudo: true
    when: only_code_deploy == "no"
  </code></pre>
  
  <p>but I get this error::</p>
  
  <pre><code>TASK: [akd_venv | pip Install packages into virtualenv]   
  *********************** 
  fatal: [vagrant] =&gt; error while evaluating conditional: only_code_deploy == "no"
  </code></pre>