title: Code within d3.json() callback is not executed
body: <p>I am trying to load a GeoJSON file and to draw some graphics using it as a basis with D3 <strong>v5</strong>.  </p>
  
  <p>The problem is that the browser is skipping over everything included inside the <code>d3.json()</code> call.  I tried inserting breakpoints to test but the browser skips over them and I cannot figure out why.</p>
  
  <p>Code snippet below.</p>
  
  <pre><code>d3.json("/trip_animate/tripData.geojson", function(data) {
  
    console.log("It just works");  // This never logs to console.
  
    //...all the rest
  }
  </code></pre>
  
  <p>The code continues on from the initial <code>console.log()</code>, but I omitted all of it since I suspect the issue is with the <code>d3.json</code> call itself.  </p>