title: Ansible does not reload group_vars when changing host group in a playbook
body: <p>I have filled an issue on the ansible repository but I would like to confirm that it is really a bug and that I am not doing anything wrong.
  <a href="https://github.com/ansible/ansible/issues/14945" rel="nofollow">https://github.com/ansible/ansible/issues/14945</a></p>
  
  <p>It seems that a variable defined in a group_vars is not reloaded when the host group change in the playbook.</p>
  
  <p>This is my playbook using ansible 2.0.1.0</p>
  
  <pre><code>├── inventory
  │   └── dev
  │       ├── group_vars
  │       │   ├── all
  │       │   ├── backend
  │       │   └── backoffice
  │       └── hosts
  ├── playbook.yml
  └── roles
      └── deploy
          └── tasks
              └── main.yml
  </code></pre>
  
  <p>The inventory in host :</p>
  
  <pre><code>[shop]
  weenect.dev ansible_user=vagrant
  
  [backend]
  weenect.dev ansible_user=vagrant
  
  [backoffice]
  weenect.dev ansible_user=vagrant
  </code></pre>
  
  <p>The tasks in the deploy role executed for each host group :</p>
  
  <pre><code>---
  - debug: msg="{{ deploy_source_folder }}"
  </code></pre>
  
  <p>And the value of this variable :</p>
  
  <p>Content of inventory/dev/group_vars/all :</p>
  
  <pre><code>---
  deploy_source_folder: "default"
  </code></pre>
  
  <p>Content of inventory/dev/group_vars/backend :</p>
  
  <pre><code>---
  deploy_source_folder: "backend"
  </code></pre>
  
  <p>Content of inventory/dev/group_vars/backoffice :</p>
  
  <pre><code>---
  deploy_source_folder: "backoffice"
  </code></pre>
  
  <p>When executing my playbook, the expected result would be :</p>
  
  <pre><code>Debug of deploy_source_folder for backend : "backend"
  Debug of deploy_source_folder for backoffice : "backoffice"
  Debug of deploy_source_folder for shop : "default"
  </code></pre>
  
  <p>But instead I have :</p>
  
  <pre><code>Debug of deploy_source_folder for backend : "backend"
  Debug of deploy_source_folder for backoffice : "backend"
  Debug of deploy_source_folder for shop : "backend"
  </code></pre>