How to inject the @request into a service?

Question

When I try to inject the @request into any of my services, I get this exception:

ScopeWideningInjectionException: Scope Widening Injection detected:

Answer 1

I think there may have been some misunderstanding about what the official documentation says. In most cases you do want to inject the request directly with a scope="request" attribute on the service element. This makes the Scope Widening go away.

or in yml

zayso_core.openid.rpx: 
    class: Zayso\CoreBundle\Component\OpenidRpx
    public: true
    scope: request

It's only in specific special cases such as Twig extensions where you need to inject the container.

And kernel is not even mentioned in the page on scopes. Injecting the kernel is far worse (conceptually) than injecting a container.

UPDATE: For S2.4 and newer, use @Blowski's answer below.