cant extract from html file

[klydream]

<div
>
  <table class="table" ng-hide="collapsed || filesVM.files.length == 0">
    <tr>
      <th>{{_('Filename')}}
      <small class="text-muted">({{ (filesVM.files | filter:fileSearch).length }} files)</small>
      </th>
    </tr>
  </table>

</div>

babel doesn't work, but it can work as below

<div
>
  <table class="table" ng-hide="collapsed || filesVM.files.length == 0">
    <tr>
      <th>{{_('Filename')}}
      <small class="text-muted"></small>
      </th>
    </tr>
  </table>

</div>

with config [jinja2: /templates/.html] encoding = utf-8 extensions = jinja2.ext.autoescape, jinja2.ext.with_

[zgoda]

This should be reported in python-babel/babel. Does plain old xgettext work ok in this case?