Problem/Description¶

Following scenario:

- new TYPO3 project
- based on TYPO3 core >= v12.4.9
- without any deprecated code (yeah, it's possible)
- throws the following error which makes the instance not useable anymore:

Uncaught TYPO3 Exception Attribute class "TYPO3\CMS\Backend\Attribute\Controller" not found
thrown in file /var/www/html/vendor/symfony/dependency-injection/Compiler/AttributeAutoconfigurationPass.php
in line 100

It looks like this is a regression which was introduced within the backport of #102631 (Introduction of #[AsController] attribute)

ToDo(s)¶

The TYPO3 core should/must run without the need of enabled typo3/class-alias-loader composer-plugin.

Suggestion: re-add `TYPO3\CMS\Backend\Attribute\Controller` to have a longer transitionphase.

Furthermore, I don't know whether it would be better to see the use of the composer plugin typo3/class-alias-loader as mandatory in TYPO3 composer projects.