XCode11 iMessage app not compiling due open(_:options:completionHandler:) is unavailable in application extensions

I just launched Touchgram v1.0 last week, which is 99% iMessage app extension, and am trying to update to XCode11.


I'm now getting an error `open(_:options:completionHandler:) is unavailable in application extensions`


I have confirmed this occurs even in a trivial sample that tries to launch a web URL from an iMessage app:


For example:

        let openSel = #selector(UIApplication.open(_:options:completionHandler:))
        while (responder != nil){
            if responder?.responds(to: openSel ) == true{
                // cannot package up multiple args to openSel so we explicitly call it on the iMessage application instance
                // found by iterating up the chain
                (responder as? UIApplication)?.open(url, completionHandler:handler)  // perform(openSel, with: url)
                return
            }
            responder = responder!.next
        }

This is fairly dire as it prevents building even a trivial update.

This technique is used to launch our Settings app as well as linking to web pages from messages.


Help!
thanks, Andy Dent