I'm not seeing Swift.Error definition

On p. 272 it says, “Command-click on Swift.Error protocol to see its definition from the swift standard library. You will find it is an empty protocol.”

When I command-click on Swift.Error I don’t get a definition, I get this strange code:

precedencegroup BitwiseShiftPrecedence {
    higherThan: MultiplicationPrecedence
}

precedencegroup FunctionArrowPrecedence {
    associativity: right
    higherThan: AssignmentPrecedence
}

precedencegroup AssignmentPrecedence {
    associativity: right
    assignment: true
}

It continues on for tens of thousands of lines. What’s going on? Wheres the definition?

You have probably clicked on Swift. Click on Error.

struct Bar : Swift.Error {
    
}

Error is the protocol; Swift is the module that contains it.

Ahh ok, I was clicking so it highlighted them both but now I just clicked on error and it gave me this:
public protocol Error {
}
That looks right