title: sass @if variable-exists import else error message
body: <p>I wanna know if it is possible to me get a message or alert in my terminal saying the font was not loaded, is that possible? right now I am not getting any error message.</p>
  
  <p><strong>font variable:</strong></p>
  
  <pre><code>$font-url: 'http://fonts.googleapis.com/css?family=Open+Sans:100,300,400,700,900';
  </code></pre>
  
  <p>if conditional</p>
  
  <p><strong>// Import if Google Fonts URL is defined</strong></p>
  
  <pre><code>@if variable-exists(font-url) {
        @import url($font-url);
  }
  </code></pre>