code: private function extractFail($output)
      {
          if (preg_match('%##teamcity\[testFailed.*\]%', $output, $matches)) {
              preg_match(
                  "/##teamcity\\[testFailed.*name='(.*)' message='(.*)' details='\\s*(.*)' flowId=.*/",
                  $output,
                  $matches
              );
              $matches = $this->replaceEscapedChars($matches);
              $fail = sprintf(
                  'Test Name: %s' . PHP_EOL . 'Failure Message: %s' . PHP_EOL . 'Trace:' . PHP_EOL . '%s',
                  $matches[1],
                  $matches[2],
                  $matches[3]
              );
              return $fail;
          }
          return 'No failure output was detected by Humbug, but a failure was reported by PHPUnit.';
      }
docs: Extract failure details and reformat into human readable form.
  
  @param  string $output
  @return string