Works on Simulator, fails on device: error: WatchKit App doesn't contain any WatchKit Extensions

Question

I am seeing the following error when trying to run a project on a real device, in the simulator it runs fine.

error: WatchKit App doesn't contain any WatchKit Extensions. Verify that the value of NSExtensionPointIdentifier in your WatchKit Extension's Info.plist is set to com.apple.watchkit

Things which may or may not be relevant

• I am using cocoa pods in both the watch and main app target
• The project is mostly objective-c but has a few swift files
• Xcode 8.1 (8B62)
• Device Software Versions: iOS 10.1.1 & WatchOS 3.1
• Deployment Info > Deployment Target: iOS 10.0 watchOS 3.0

Things I’ve tried

• I have checked several times that all the correct files belong to the watch target. I may have missed something here, but I assume it wouldn’t run on the simulator if this was the case
• Bundle identifiers
  • main app’s identifier: < app id >
  • watch app’s bundle identifier: < app id >.watchkit
  • watch app’s WKCompanionAppBundleIdentifier: < app id >
  • watch extension’s bundle identifier: < app id >.watchkit.extension
  • watch extension’s NSExtension>NSExtensionAttributes>WKAppBundleIdentifier: < app id >.watchkit
• NSExtension>NSExtensionPointIdentifier: com.apple.watchkit
• WKWatchKitApp is set to YES in both the Watch Extension and the Watch App
• I have removed and re-added the .appex from Build Phases>Embed App Extensions
• Ensuring Mach-O Type is set to executable in all targets
• Re-installing pods as described in this answer
• Clearing derived data
• Clearing build folder
• Restarting Xcode
• I tried an archive and this failed with the same error

In lieu of an answer, advice on debugging / troubleshooting this would be appreciated too.

Answer 1

I encountered this error, with 3 other errors.

Turned out the problem is that Valid Architectures is set incorrectly. Under Build Settings, make sure Valid Architectures includes i386 and armv7k.

Once that is fixed, the watch extension will be build, and all errors gone.

Answer 2

I've seen this intermittently, but usually rebuilding a second time fixed it. I've never got to the bottom of why.

I've always assumed it's a bug in Xcode.

Sorry can't be more help, but you're not alone in seeing this.