`FileError.AccessDenied` is a unique value in a unique error set. `error.AccessDenid` has not been defined anywhere and hence is just given an integer value at some point by the compiler.
As I stated before, this error wouldn't even exist in the first place in no codebase ever: look how the method that fails returns a `FileError` and not an `anyerror`
It could be rightly argued that it still shouldn't compile though.