$requirements['curl']['description']=$t('Simpletest could not be installed because the PHP <a href="@curl_url">cURL</a> library is not available.',array('@curl_url'=>'http://php.net/manual/en/curl.setup.php'));
$requirements['hash']['description']=$t('Simpletest could not be installed because the PHP <a href="@hash_url">hash</a> extension is disabled.',array('@hash_url'=>'http://php.net/manual/en/book.hash.php'));