Usage of no-implicit-copy value that the compiler can't verify

Development Compiler
1

The following code snippet raises the following compiler error:

"Usage of no-implicit-copy value that the compiler can't verify. This is a compiler bug. Please file a bug with a small example of the bug"

protocol TestProtocol {
    var y: Int { get }
}

func work(x: borrowing TestProtocol) {
    x.y
}

I understand why this might be problematic for compiler, but I was somewhat confused by the message.

Should I file a bug with this?