title: Magento 2 get custom Product Attribute from shipping
body: <p>In the Carrier Model, pulling the products works via <code>$request-&gt;getAllItems()</code> and then getting the Product <code>$item-&gt;getProduct()</code>. 
  I can't seem to figure out <strong>how to pull a custom product attribute.</strong> </p>
  
  <pre><code>    $item-&gt;getProduct()-&gt;getAttribute('custom_attr'); // nothing 
      $item-&gt;getProduct()-&gt;getResource()-&gt;getAttribute('custom_attr'); // uses up 3GB memory and dies 
      $item-&gt;getProduct()-&gt;getCustomAttributes(); //empty array  
      $item-&gt;getProduct()-&gt;getExtensionAttributes(); //empty array 
  </code></pre>
  
  <p>also tried creating the extension_attributes.xml </p>