Swift Sdtlib tool error: Task failed with exit code 1

Question

So randomly after several hours of work this morning on my app, Xcode just stopped letting me test my app on my iPhone. But I can still test it in the simulator.

Now

Answer 1

In my case, it was solved by

1. Close Xcode.
2. Clean Derived data.
3. Open Xcode.
4. Clean Product.
5. Run your app.