private function renderBuildVariablesTable()
 {
     $viewer = $this->getRequest()->getUser();
     $variables = HarbormasterBuild::getAvailableBuildVariables();
     ksort($variables);
     $rows = array();
     $rows[] = pht('The following variables can be used in most fields. To reference ' . 'a variable, use `${name}` in a field.');
     $rows[] = pht('| Variable | Description |');
     $rows[] = '|---|---|';
     foreach ($variables as $name => $description) {
         $rows[] = '| `' . $name . '` | ' . $description . ' |';
     }
     $rows = implode("\n", $rows);
     $form = id(new AphrontFormView())->setUser($viewer)->appendRemarkupInstructions($rows);
     return id(new PHUIObjectBoxView())->setHeaderText(pht('Build Variables'))->appendChild($form);
 }