ChainUserProvider exists in Symfony since forever, but there is a relatively new feature in Security Component - AttributesBasedUserProviderInterface which allows to pass custom array from authenticator to the user provider. Unfortunately it does not work if the instance of class that implements AttributesBasedUserProviderInterface is "hidden" behind ChainUserProvider. The method ChainUserProvider::loadUserByIdentifier passes always only its first argument to the chained provider and therefore we loose features intorduced by the AttributesBasedUserProviderInterface.

My solution to this problem assumes that we treat ChainUserProvider as a "proxy class" to the internal providers, so we should pass all arguments passed to ChainUserProvider::loadUserByIdentifier to the <internal_provider>::loadUserByIdentifier.