These four symbols override something from their parent in an incompatible way. I think the best way forward would be to manually define extensions to those types using a slightly different name, but I’m not sure.
Some of those have been helpfully cleaned up by spec authors, but I’ve also manually patched the ones that haven’t been (such as BeforeUnloadEvent.returnValue) to a different name (here, returnValueAsString)
These four symbols override something from their parent in an incompatible way. I think the best way forward would be to manually define extensions to those types using a slightly different name, but I’m not sure.
https://github.com/swiftwasm/DOMKit/blob/070f99efca195eaa38f46beeb4dc46ca1d6ce04b/Sources/WebIDLToSwift/IDLBuilder.swift#L89-L93