I'm trying to add a watchOS app and watch widgets to an existing iOS project, similar to what's shown in wwdc2022-10050. The widget works fine when I select the iOS scheme, but when I switch over to the watchOS widget scheme, Xcode fails to generate a preview and gives this error. I'm not sure how to enable support for previews properly.
UnsupportedProductTypeError: Previews not supported for WeatherNewWidget Watch
Previews can be defined in applications, frameworks, Swift packages, or dynamic libraries
productType = com.apple.product-type.extensionkit-extension
buildable = WeatherNewWidget Watch.appex