Unsupported generic tuple error when using Scala 3 code in Scala 2

[jadenPete]

Reproduction steps

Scala 2 version: 2.13.16 Scala 3 version: 3.6.3

1. Clone this minimum reproducability case: https://github.com/jadenPete/scala-unsupported-generic-tuple-bug-reproduction

2. Run sbt compile

3. Observe the following compilation error:

[error] Unsupported Scala 3 generic tuple type scala.Tuple in bounds of type MirroredElemLabels; found in trait scala.deriving.Mirror.

Problem

I'd expect this to compile. I acknowledge that this is an unusual use case (Foo should be an object, not a case object), but we stumbled upon it during our Scala 2 -> Scala 3 migration and I thought it'd be valuable to report. If this is expected behavior and not a bug, feel free to close this issue.