title: How to access env variable in functional component?
body: <p>I would like to define a default value if a prop is not passed to my functional component.
  This default value is an environement variable.</p>
  <p>When I try the following, compilation will throw an error <code>TypeError: Cannot read property 'env' of undefined</code></p>
  <pre><code>&lt;template functional&gt;
      &lt;div class=&quot;header__small&quot;&gt;{{ props.header_small ? props.header_small : process.env.VUE_APP_DEFAULTHEADER }}&lt;/div&gt;
  &lt;/template&gt;
  </code></pre>
  <p>The same happens if I try with <code>parent.process.env.VUE_APP_DEFAULTHEADER</code></p>
  <p>The env variable are working fine in every other classic component accross the app. It just won't work with functional ones.
  Ternary operator to define a default value works well also if I pass it any other value, just not process.env.</p>