BackendTrait for Suggesters fails on logging Exceptions

The patch isn't correct.

We use the Search API internal logger here, not Drupal's.

This way you skip a lot of logic:

  protected function logException(\Exception $exception, $message = NULL, array $variables = [], $severity = RfcLogLevel::ERROR, $link = NULL) {
    // Use a default value if $message is not set.
    if (empty($message)) {
      $message = '%type: @message in %function (line %line of %file).';
    }

    if ($link) {
      $variables['link'] = $link;
    }

    $variables += Error::decodeException($exception);

    $this->getLogger()->log($severity, $message, $variables);
  }

The code works as it is. I think the correct fix is to actively tell PHPCS that this isn't an error!

You're right. I didn't notice that getBackend() has to be static as it is called in a static context.