Change record status: 
Project: 
Introduced in branch: 
9.5.x
Introduced in version: 
9.5.0
Description: 

Fast 404s emitted by \Drupal\Core\EventSubscriber\Fast404ExceptionHtmlSubscriber are now cacheable in Drupal's page cache like a regular 404 response. Sites that have fast 404s enabled should not need to make any changes to benefit.

The \Drupal\Core\EventSubscriber\Fast404ExceptionHtmlSubscriber constructor has been changed to support this. The second argument is a \Drupal\Core\Cache\CacheTagsInvalidatorInterface service instead of a \Symfony\Component\HttpKernel\HttpKernelInterface

Impacts: 
Module developers