title: TypeError: flatMap is not a function
body: <p>I was trying to install parcel to run my own npm package but I get the following error when starting the HTML with parcel lib:</p>
  <pre><code>TypeError: [(...previousDevDepRequests.entries(...))].filter(...).flatMap is not a function
      at Object.run (C:\Users\ishantr\AppData\Roaming\npm\node_modules\parcel\node_modules\@parcel\core\lib\requests\AssetRequest.js:94:122)
  </code></pre>
  <p>I am on v10.16.0, and my index template is something like this:</p>
  <pre><code>&lt;img src=&quot;xxx.jpg&quot; alt=&quot;&quot; class=&quot;some_class_name&quot;&gt;
  &lt;script src=&quot;./index.js&quot;&gt;&lt;/script&gt;
  </code></pre>
  <p>It calls the js file to run some business logic.</p>