"Recursive reference to itself" with Optional and ArcPointer

Mojo
1

Hello, I have the following struct:

struct S(Movable):
    var x: Optional[ArcPointer[S]]

The code doesn’t compile, the error message is: “struct has recursive reference to itself“

Am I overlooking something? The following compiles without errors:

struct S(Movable):
    var x: ArcPointer[S]
2

This is an ongoing compiler bug that the team is aware of.