`export`ed parameterized types give type mismatch errors when used in method/function parameter positions.

[lorandszakacs]

3.0.0-RC1

Minimized code

object example {
  trait MyType[A]
}

object bug {
  export example.MyType
  def bug[A](m: MyType[A]): MyType[A] = m //type mismatch
  val bug2: MyType[String] => MyType[String] = m => m //type mismatch

  //it works when referencing the original type in the parameter position.
  def thisWorks[A](m: example.MyType[A]): MyType[A] = m
  val thisWorks2: example.MyType[String] => MyType[String] = m => m
  val thisWorks3: MyType[String] = (??? : MyType[String])
}

Output

Type error:

[error] -- [E007] Type Mismatch Error: src/main/scala/export_example/myTypeclassExports.scala:9:40 
[error] 9 |  def bug[A](m: MyType[A]): MyType[A] = m
[error]   |                                        ^
[error]   |                              Found:    (m : export_example.bug.MyType[A])
[error]   |                              Required: export_example.bug.MyType[A]
[error] one error found
[error] one error found
[error] (phms-util-config / Compile / compileIncremental) Compilation failed
[error] Total time: 2 s, completed Mar 28, 2021, 9:36:03 PM
//idem for bug2

Expectation

That the code type-checks without referencing the full original type in parameter position.

[smarter]

The typer output for export example.MyType is:

final type MyType = example.MyType

The fact that the type parameter doesn't show up here is suspicious /cc @odersky