APFS to create a separate partition Install Sequoia in new partition Install macOS 26 Beta (enable betas) Xcode Coding Assistant works.

First suggestion seems to require an addition to the RealityKitContent > Package. ...], swiftLanguageModes: [.v5] You may need to Clean. Xcode seems to incorrectly remember all the Build fails.

It would be good if sample code was updated with version controlled embedded source so everybody could actually understand the diffs.

You can use a PersistentModel object in XCTest. You have to create a ModelContainer as a property of XCTestCase - see the default template code that is supporting the Item model. Seems you have to pretend with @MainActor. For the config enabled store in memory only. Use container.mainContext.insert() to add objects to the model.

I went back in time to Xcode 12.4 on Catalina, the error message is different, it refers to contracts in need of signing. Not UUID (which 12.5 does). I now wondering if it is because I am still a member of organisations that are no longer program members. So wondering if the error is triggered by any organisation that hasn't signed, rather than the one for which I'm notarising code for. In developer.apple, any organisation that I have been a member of is still listed. However, Xcode now only shows the two that are active. So there is an inconsistency. FB9206318 has the screen shots, Quinn. I'll need to figure out where to find all the arguments for altool - have not needed to know all those the details....