Symfony version(s) affected

6.4.9

Description

Since 6.4.9[1], the drupal/simplesamlphp_auth module will sometimes throw an error when attempting to log in the user:

The router "Symfony\Component\Routing\Router" cannot be warmed up because it does not implement "Symfony\Component\HttpKernel\CacheWarmer\WarmableInterface".

[1] The bug might have been introduced in 6.4.8 it never occured because there was another error (#57316)

How to reproduce

Using Drupal 10.2.7 or higher with the simplesaml_auth 4.0.0 module, try to log in.

Possible Solution

It looks like this was fixed in 7.1.2 (see #57554 and 35d085dc18b494d20b75728ecb222543e760c515), but would appreciate if this could be backported for 6.4.x.

Additional Context

Also see the related simplesamlphp_auth bug