Misleading AnyVal object error message

[nicolasstucki]

Compiler version

3.3.1

Minimized code

object Foo extends AnyVal

Output

1 |object Foo extends AnyVal
  |^^^^^^^^^^^^^^^^^^^^^^^^^
  |Foo is already defined as object Foo

Expectation

Better error message

1 |object Foo extends AnyVal
  |^^^^^^^^^^^^^^^^^^^^^^^^^
  |object Foo cannot extend class AnyVal

[scala-center-bot]

This issue was picked for the Issue Spree No. 35 of 22 August 2023 which takes place in 7 days. @iusildra, @SimonGuilloud, @sankalpgambhir will be working on it. If you have any insight into the issue or guidance on how to fix it, please leave it here.

[mbovel]

In case you guys finish working on this early, you can try to tackle #17969.