In the last submission of our application, we have received this warning :
Invalid WatchKit Support - Starting April 1, 2018, all apps submitted to the App Store for Apple Watch must be built with the watchOS 2 SDK or later
My question is to know how to to build the application with the watchOS 2 SDK?
I was thinking that is enough to build with XCODE 9.
Thank's.
Check your Deployment Target. It's likely it wasn't updated just by using a newer version of Xcode.
Also try checking Base SDK in Build Settings of your Watch Extension to make sure it is up to date.
来源：https://stackoverflow.com/questions/49174059/how-to-build-an-application-with-the-watchos-2-sdk