title: How do you remove read-only files with grunt clean?
body: <p>I have a grunt build script which has a <code>clean</code> task to remove some cache files. Currently this task fails because the files it is supposed to remove are read-only.</p>
  
  <p><strong>How do you make <code>grunt clean</code> remove read-only files?</strong></p>
  
  <p>For those who are curious, the output from my command is as follows:</p>
  
  <pre><code>Running "clean:templates" (clean) task
  Verifying property clean.templates exists in config...OK
  Files: app/cache/dev/twig, app/cache/prod/twig -&gt; templates
  Options: force
  Cleaning "app/cache/dev/twig"...Deleting app/cache/dev/twig...ERROR
  ERROR
  &gt;&gt; Error: Unable to delete "app/cache/dev/twig" file (EPERM, operation not permitted 'app/cache/dev/twig').
  Warning: Clean operation failed. Use --force to continue.
  </code></pre>
  
  <p>The files in the <code>app/cache/dev/twig</code> folder are read-only and can be deleted with the command <code>rm -rf app/cache/dev/twig</code>.</p>