genrule</code> in three formats:
  </p>

  <ul class="bulleted-list">
    <li>
      <span>
        As a string; the simplest format, since there's only one command that's
        run.
      </span>
    </li>
    <li>
      <span>
        As a list, it's a sequence of commands run one after another if the
        preceding ones are successful (i.e. it's effectively shorthand for
        <code class="code">' &amp;&amp; '.join(cmd)</code>
      </span>
    </li>
    <li>
      <span>
        As a dict, the ke