Has anyone managed to get Copilot working using the new ACP integration in Xcode 26.6 and Xcode 27 beta? I have tried setting it up using the path to the copilot binary as instructed and the flags --acp --stdio but Xcode just displays a "Your request couldn't be completed" error: JSON-RPC global stream failed: The operation couldn’t be completed. (IDEIntelligenceProtocol.JSONRPCElement.Error error 1.) I am running the latest version of copilot cli and it works in many other IDEs.

I have an app with thousands of snapshot tests, technically these are unit tests rather than UI tests, they take a snapshot of a view controller and compare the resulting image to a known image and fail if there are any changes. The app is not using Liquid Glass (yet) so I have added UIDesignRequiresCompatibility to my Info.plist file however this does not seem to be respected during my unit tests. Is there any way to run my snapshot tests on an iOS 26 simulator without using the new Liquid Glass UI?

Is there any way to use outline disclosure sections in a UICollectionViewDiffableDataSource without having to make all apply(_ snapshot:) calls from the main thread? Whenever I collapse or expand a section I get a warning about mixing main queue/off-main queue updates: Warning: applying updates in a non-thread confined manner is dangerous and can lead to deadlocks. Please always submit updates either always on the main queue or always off the main queue I understand what this means, but I am applying my section snapshots on a background queue to avoid interrupting the UI, it seems like the expand/collapse updates use the main queue and I cannot find any way to make it use the same queue as my other updates. Does this mean I must apply my own updates on the main queue now as well?

Is it possible to build a SwiftUI app on macOS 11 that uses new APIs in macOS 12? I have tried using an #availability check to only use the new APIs on macOS 12, but am getting a crash saying 'symbol not found' when running that app on macOS 11. Do I need to develop on macOS 12?