I also posted this on StackOverflow but have not received any answers; copying from there.
I'm using Xcode 9.1 and trying testing on an iPhone 7 Plus with iOS 11.1.2 and an Apple Watch 1st Generation with watchOS 4.1 on Mac OS Sierra 10.12.6. App made in Swift 4.
If I only run the mobile app on the physical iPhone, the connection with Xcode stays on, so I'm able to see crash logs.
But, when I run the watch app on the physical Watch, the connection with Xcode cuts off immediately (after successfully building and installing), preventing me from seeing any crash logs.
But, when I run the watch app on the simulator Watch or iPhone, the connection with Xcode stays on, so I'm able to see crash logs.
What I've tried: I've deleted archive data, cleaned the project, restarted Xcode, restarted computer, restarted physical Watch, and restarted physical iPhone, and issue has still not been fixed.
The app takes about 5 minutes to run, if that matters. This is an app at work, so reinstalling Xcode would require me to go to the IT guy and have a specific image he has to be installed, and it takes a long time to even be able to see him. I don't have the time to go through all that right now.