Typo in \Drupal\user\Plugin\Block\UserLoginBlock, {@inheritdo} instead of {@inheritdoc}

  /**
   * {@inheritdo}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, array $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container,
      $container->get('request')
    );
  }

Ref. https://drupal.org/node/1354#inheritdoc