title: Inject an error message to errors object
body: <p>Is there a way to inject an error message so we can show it on a view with <code>$errors</code> instance, on a redirection?</p>
  
  <pre><code>$errors-&gt;all(); // e.g. to have it here
  </code></pre>
  
  <p>Which I tried:</p>
  
  <pre><code>return Redirect::to('dashboard')
                      -&gt;with('errors', 'Custom error');
  </code></pre>
  
  <p>But actually will throw an error:</p>
  
  <pre><code>Call to a member function all() on a non-object
  </code></pre>