Array undefined index.

phpcs fails on the following code:

$plugin_derivatives[$machine_name] = array(
  'id' => $base_plugin_id . PluginBase::DERIVATIVE_SEPARATOR . $machine_name,
  'label' => $this->t('Search api view: %view_name, display: %display_title', ['%view_name' => $view->label(), '%display_title' => $display_info['display_title']]),
  'description' => $this->t('Provides a facet source.'),
  'view_id' => $view->id(),
  'view_display' => $name,
) + $base_plugin_definition;

It works when changing the array syntax to a short array syntax.