scalac hangs in phase typer

[gdiet]

Using Scala 2.13.5 (on Ubuntu Java 11.0.10 x64)

object CompileHangs {
  def read1(): LazyList[Either[(Int, Int), String]] = ???
  def read2(): Option[LazyList[Either[(Int, Int), String]]] = ???

  def read(): LazyList[Either[(Int, Int), String]] =
    read1().flatMap {
      case Right(_) => LazyList()
      case Left(value) =>
        read2().getOrElse(
          Vector(Left(value))
        )
    }
}

compiling with scalac hangs in the typer phase (as shown by scalac -Ydebug). Additional observations:

• I would expect a type error in the line containing Vector.
• If I replace the tuple (Int, Int) with a simple Int, the example compiles. I would have expected the type error, but maybe there is some implicit conversion at work here?
• If I replace Vector with LazyList, everything works as expected.

[joroKr21]

That looks like a duplicate of #10908