Drupal 8 - Breadcrumb Preprocess and Cache

breadcrumb-cache.theme

function theme_preprocess_breadcrumb(&$variables) {
  if (($node = \Drupal::routeMatch()->getParameter('node')) && $variables['breadcrumb']) {
    $variables['breadcrumb'][] = [
      'text' => $node->getTitle() 
    ];
    $variables['#cache']['contexts'][] = 'url.path';
  }
}

breadcrumb-nocache.theme

function theme_preprocess_breadcrumb(&$variables) {
  if (($node = \Drupal::routeMatch()->getParameter('node')) && $variables['breadcrumb']) {
    $variables['breadcrumb'][] = [ 'text' => $node->getTitle() ];
  }
}