You should also check that the class you are declaring doesn't exist (and that the bc one exists too).

@Taluu As far as I investigated yesterday that should not be a Problem as composer makes it possible to have multiple classes within the same namespace. And since the FC layer is needed when the namespaceless classes are available that might be a viable solution. But this is more a POC so far to see if this is even possible this way. I am not sure whyclass Test extends \PHPUnit\Util\Test does not work in thedefault.phpt file, I know there is some caching involved in the bridge.

Thanks for this PR!

Unfortunately, this kind of approach was prev. rejected, seethis comment:

[...] but the PhpUnit namespace is not our vendor, so me must not get there. An example of a nasty side effect of using class_alias: phpunit 6 would behave differently when doing class_exists('PHPUnit_Util_ErrorHandler') with or without the bridge.

PS: you should add#21125 as a fixed ticket.

Mhm, then I can only think of making a bridge version which is only PHPUnit 6 compatible or move the FC layer to a separate repository.

As I understood@nicolas-grekas in#21663 such change as this can anyway go only into 3.3?

In my PR I wrote the FC layer in the Bridge. The FC classes expanded PHPUnit's.

But this breaks the Interface and I think that is waht you were stuck with?

Yes, you're right. I think that is the current impasse.

Closing on favor of#21694