This is straight from an Xcode generated project. I recreated that project with another name, still happens.
I tried to delete devices and added devices (and tried to use a device I haven't used before) to no avail.
Upon building the watchkit app, I try to run it in the similator (in this case 8Plus and 42mm 3rd generation). The devices boot up normally but the app will not start, instead
///
Failed to install the requested application
An application bundle was not found at the provided path.
///
Appears. If I select to run / debug the iOS counterpart, it will load fine, it will upload the app to the simulated paired watch and I can test the app, but I can't (easily) debug or see log messages.
Again, this happens with a plain vanilla xcode generated project.
Log from the coreSimiulation
Apr 20 15:48:50 13inch com.apple.dt.Xcode[596] <Error>: installApplication:withOptions:error:: Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory" UserInfo={NSLocalizedFailureReason=An application bundle was not found at the provided path., NSLocalizedRecoverySuggestion=Provide a valid path to the desired application bundle., NSLocalizedDescription=Failed to install the requested application}
It seems this is a problem when staging the app for the upload to the simulator (seems that Xcode does it differnently when running the watchkit app)
I just compiled an old app I had finished 2 years ago and that shows the same behavior.
I guess I need to report as a bug if nobody has a workaround.
Tom