Async Initializers

Hi,

I setup swift-format today and got the error error: file contains invalid or unrecognized Swift syntax. for a lines containing init() async. I have included sample code below running from a fresh swift package init --type executable which runs fine on MacOS from the either the Terminal or Xcode but I didn't see any mention of async initializers in the Language Reference. I am wondering if this is a bug/bad practice and should be avoided or just not a full supported feature yet?

@main
struct AsyncInit {
    public static func main() async {
        print("main")
        _ = await Delayed()
        print("initialized")
    }   
}
struct Delayed {
    init() async {
        try! await Task.sleep(nanoseconds: 1_000_000_000)
        print("Delayed")
    }
}

Thanks in advance,
Zane