code: protected function buildNotInConsole()
      {
          if (!$this->stats['notInConsole']) {
              return '';
          }
          $errors = $this->errorHandler->get('errors');
          $lis = array();
          foreach ($errors as $err) {
              if (\array_intersect_assoc(array(
                  // at least one of these is true
                  'category' => 'fatal',
                  'inConsole' => true,
                  'isSuppressed' => true,
              ), $err->getValues())) {
                  continue;
              }
              $lis[] = '<li>'.$err['typeStr'].': '.$err['file'].' (line '.$err['line'].'): '
                  .($err['isHtml']
                      ? $err['message']
                      : \htmlspecialchars($err['message']))
                  .'</li>';
          }
          if (!$lis) {
              return '';
          }
          $count = \count($lis);
          $header = \sprintf(
              '%s %s captured while not collecting debug log',
              $this->stats['inConsole'] || isset($this->stats['counts']['fatal'])
                  ? 'Additionally, there'
                  : 'There',
              $count === 1
                  ? 'was 1 error'
                  : 'were '.$count.' errors'
          );
          $html = '<h3>'.$header.'</h3>'
              .'<ul class="list-unstyled indent">'."\n"
              .\implode("\n", $lis)."\n"
              .'</ul>';
          return $html;
      }
docs: Returns summary for errors that occurred while log collect = false
  
  @return string