Documentation wise https://symfony.com/doc/3.4/console/usage.html still mentions these options for symfony < 4. Maybe we should remove the page for 3.4 as well and add this part instead: https://symfony.com/doc/current/console.html#the-console-app-env-app-debug

@Tobion It's similar to the new directory structure: the old translations/templates locations are still part of the 3.4 docs but the new ones are not, while they are actually supported since 3.4.
I believe we consider APP_ENV a Symfony 4 thing "officially", even if we started experimenting it in 3.4

#466 will contain these changes in a 4.2 recipe. I'd suggest either to wait for it to be (tweaked and) merged, or create the missing 4.2 recipe for console instead.

Should we really do this? In symfony/symfony#28984, people are complaining removing these attributes make the console harder to use for them. We did deprecate the options from core - and this was the thing to do to me also. BUT shouldn't we continue to allow using them here?

That's for new projects or people manually upgrading to new versions of these recipes. A new project should be free of deprecations by default, that's my main argument here. No stronger opinion, but that's what we used to do.

There is another way to be free from the deprecations: extract these from $argv right into bin/console.

Sure, why not. But we have to ensure it'll play well with #466. Unless we don't plan to finish & merge #466 soon, we might no need this one but directly see how to solve your comment within?

I think we can close, #481