I created a brand new empty apple watch app in XCode 7.0 beta 3 (7A152u).
In the simulator it runs fine, however I can't get it to work on a real apple watch. The app launches but watch device is stuck on a spinning wheel loading screen and the xcode debugger says nothing about what's going on.
My apple watch runs the latest watchOS 2.0 beta, my iphone is a 5s with the latest iOS 9.0 beta.
Any idea on what is happening and how to debug this issue?
I have already tried creating a new project, cleaning the project, deleting the app on the iphone, restarting my mac, the iphone and the apple watch.
UPDATE July 28 2015:
Updating to the beta 4 (both for iOS9, watchOS2 and XCode7) didn't solve the issue. Now the app is stuck in the Installing... state in the iOS Watch app.
I had this problem and I'm currently experiencing it at random times.
Check out my answer to this question which may help you: Debug WatchKit on real Apple Watch - Nothing happens
The trick is to force close the app before running it again. Xcode thinks that it's not running and does not stop it or anything else. This is most likely why we don't get any error message or warning.