I'm interested in adding a Watchkit Extension to my existing app already in the app store. I've done my research, followed some tutorials, and now am ready to actually implement.
The problem I'm having is, I can't seem to add a Watchkit App to my existing project and get it to run in the simulator. If I start a new project and do some tutorials or whatever, the Watchkit App runs fine. Adding to my existing project, I just get a black screen in the simulator window. Not even the status bar is present. http://i.imgur.com/kG7H06i.png
Only lead I have so far is: In the debug navigator, I get "Waiting to Attach" every time I try and launch the app. http://i.imgur.com/vYLfJN8.png
Any help on this would be appreciated. I reseting my simulators, tried deleting my simulators and then reinstalling. Double checked that bundle identifiers and versions match. Target for the WatchKit App and Extension are both set to 8.2 (I was getting an error setting to 8.3). Target on the main app is 6.0, but I tried bumping this up to 8.2 and had the same results.
Thanks!
EDIT: Before this is marked as a duplicate of How to run a WatchKit App, I do want to mention that I'm running the "Watchkit App" Scheme, and I do not have a status bar like in the window like he does.
Are you using iOS 8.2 simulator ?
I had similar error, switching to simulator with iOS 8.3 fixed it for me.
Check that your build target is the Watchkit App. I had it set to the main app so the main app was launching in the sim, but the watch app was blank.
referenced here.
I am also running into a similar problem but not on the simulator but on the Apple Watch device. Try setting Skip Install to NO in the WatchKit App target settings
After working with Apple, it appears as if this was an issue with Xcode creating the target. Our app is several years old, and for some reason when creating any new target, the Wrapper Extension is set to "app" every time. This has caused us issues in the past with trying to add testing targets as well.
We were able to fix the issue by going to the Watchkit Extension target, and changing the Wrapper Extension from "app" to "appex". Make sure you leave the Watchkit App target to "app". We asked why Xcode wasn't doing this automatically for this particular project, and it's because the overall project target has the Wrapper Extension set. If you create a new project, you'll notice that Xcode now leaves this blank.
Hope this helps someone else.
Sometimes, restarting Xcode solves the problem.
Even if everything is configured correctly, it may take 20 seconds to attach the process to the debugger.
I tried everything but nothing helped. Then I backed up the watch app and watch extension folders. After that I removed the watch app and watch extension targets and created new targets. Then I restored the files from the backup. It's an awkward approach but it solved the "waiting to attach" problem.
Xcode 10.0; Swift 4.2; iOS 12.0
I had the same issue with Apple Watch simulator. What actually solved it was deleting the default Siri watch face from the Watch App on the iPhone simulator.
来源：https://stackoverflow.com/questions/29926893/getting-black-screen-on-watchkit-simulator-and-waiting-to-attach-when-adding-t