Issue with the "session" service

[javiereguiluz]

When upgrading a Symfony app to 3.3.4 + Flex and using HWIOAuthBundle, I saw this error message:

!!  Fatal error: Uncaught Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException:
!! The service "hwi_oauth.resource_owner.twitter" has a dependency on a non-existent
!! service "session". in
!! <my-project>/vendor/symfony/dependency-injection/Compiler/CheckExceptionOnInvalidReferenceBehaviorPass.php:31
!!
!!  Stack trace:
!!  #0 <my-project>/vendor/symfony/dependency-injection/Compiler/AbstractRecursivePass.php(57): Symfony\Component\DependencyInjection\Compiler\CheckExceptionOnInvalidReferenceBehaviorPass->processValue(Object(Symfony\Component\DependencyInjection\Reference), false)
!!  #1 <my-project>/vendor/symfony/dependency-injection/Compiler/CheckExceptionOnInvalidReferenceBehaviorPass.php(35): Symfony\Component\DependencyInjection\Compiler\AbstractRecursivePass->processValue(Array, false)
!!  #2 <my-project>/vendor/symfony/dependency-injection/Compiler/AbstractRecursivePass.php(64): Symfony\Component\DependencyInjection\Compiler\CheckExceptionOnInval in <my-project>/vendor/symfony/dependency-injection/Compiler/CheckExceptionOnInvalidReferenceBehaviorPass.php on line 31
!!

The error message is correct, because the session service doesn't exist:

$ ./bin/console debug:container session

 Select one of the following services to display its information:
  [0] argument_resolver.session
  [1] security.authentication.session_strategy
  [2] security.logout.handler.session

The HttpFoundation 3.3.4 component is installed in the app, but the session service doesn't exist.

---

For comparison, the Symfony Demo app, which uses the exact same 3.3.4 version, but doesn't use Flex, has the session service defined:

$ ./bin/console debug:container session

Information for Service "session"
=================================

 ---------------- --------------------------------------------------
  Option           Value
 ---------------- --------------------------------------------------
  Service ID       session
  Class            Symfony\Component\HttpFoundation\Session\Session
  Tags             -
  Public           yes
  Synthetic        no
  Lazy             no
  Shared           yes
  Abstract         no
  Autowired        no
  Autoconfigured   no
 ---------------- --------------------------------------------------

[Pierstoval]

Doesn't the framework.session extension configuration has to be specified at least with null to be enabled?

[xabbuh]

Yes, by default it is disabled (the Standard Edition enables is explicitly: https://github.com/symfony/symfony-standard/blob/3.3/app/config/config.yml#L26-L29).

[xabbuh]

and the same is true for the Symfony Demo: https://github.com/symfony/symfony-demo/blob/master/app/config/config.yml#L45-L47

[javiereguiluz]

Thanks for the info. I'm closing this as "no need to fix it". But in symfony/symfony-docs#7809 I've added a note explaining that in 4.0, some important things (such as session) don't exist by default, so we must take care of that in the docs. Thanks!

[fabpot]

If HWIOAuthBundle needs a session, then we should have a recipe that enables sessions automatically (the same goes for other important bundles that need a session).

[enlego]

The same happens while installing FOSUser in Symfony Flex (it requires an inexistent session service)

[slootjes]

@fabpot What would be the correct method to create a recipe which enables sessions? I could create a meta package for it which adds a config file to set the framework.session option but I guess this could easily conflict if it was already set up.

edit: I see it's discussed here too #247 so let's keep it in there.