title: did not find expected <document start>
body: <p>Ansible is reading <code>/etc/ansible/hosts</code> file and giving errors that I don't understand.</p>
  <pre><code>ARNING]:  * Failed to parse /etc/ansible/hosts with yaml plugin: Syntax
  Error while loading YAML.   did not find expected &lt;document start&gt;  The error
  appears to be in '/etc/ansible/hosts': line 2, column 1, but may be elsewhere
  in the file depending on the exact syntax problem.
  </code></pre>
  <ol>
  <li><p>Why is ansible trying to parse this INI-style file with yaml plugin?</p>
  </li>
  <li><p>What is <code>&lt;document start&gt;</code>?  I can't find this in any documentation</p>
  </li>
  </ol>
  <p>The file looks something like this (not actual)</p>
  <pre><code>[first_group]
  host-1 ansible_host=1.1.1.1
  host-2 ansible_host=2.2.2.2
  </code></pre>
  <p>EDIT:</p>
  <p>More information:</p>
  <pre><code>ansible@ansible:~$ ansible-config dump | grep INVENTORY
  DEFAULT_INVENTORY_PLUGIN_PATH(default) = [u'/home/ansible/.ansible/plugins/inventory', u'/usr/share/ansible/plugins/inventory']
  INVENTORY_ANY_UNPARSED_IS_FAILED(default) = False
  INVENTORY_CACHE_ENABLED(default) = False
  INVENTORY_CACHE_PLUGIN(default) = None
  INVENTORY_CACHE_PLUGIN_CONNECTION(default) = None
  INVENTORY_CACHE_PLUGIN_PREFIX(default) = ansible_facts
  INVENTORY_CACHE_TIMEOUT(default) = 3600
  INVENTORY_ENABLED(default) = ['host_list', 'script', 'auto', 'yaml', 'ini', 'toml']
  INVENTORY_EXPORT(default) = False
  INVENTORY_IGNORE_EXTS(default) = {{(BLACKLIST_EXTS + ( '.orig', '.ini', '.cfg', '.retry'))}}
  INVENTORY_IGNORE_PATTERNS(default) = []
  INVENTORY_UNPARSED_IS_FAILED(default) = False
  </code></pre>