Defining service locators without a class #40861
Description
Symfony version(s) affected: 5.3.0-beta1
Description
See nelmio/NelmioApiDocBundle#1807
In Symfony 5.2, it was possible to define a service locator service without defining the actual class of the service:
In Symfony 5.3, this code fails:
The definition for "nelmio_api_doc.generator_locator" has no class. If you intend to inject this service dynamically at runtime, please mark it as synthetic=true. If this is an abstract definition solely used by child definitions, please add abstract=true, otherwise specify a class to get rid of this error.
According to the documentation, the Symfony\Component\DependencyInjection\ServiceLocator should be used in the definition.
The fix for NelmioApiDocBundle is trivial and I've already opened nelmio/NelmioApiDocBundle#1808 to address the issue. However, since this bundle broke because of a Symfony upgrade, I wanted to clarify if we want to treat this issue as a regression.