diff -ruN /Applications/Xcode_26.5.0.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/DeviceCheck.framework/Headers/DCError.h /Applications/Xcode_27.0.0-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/DeviceCheck.framework/Headers/DCError.h
--- /Applications/Xcode_26.5.0.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/DeviceCheck.framework/Headers/DCError.h	2026-04-18 22:51:00
+++ /Applications/Xcode_27.0.0-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/DeviceCheck.framework/Headers/DCError.h	2026-05-24 13:21:05
@@ -32,6 +32,7 @@
     /// - You call
     /// ``DeviceCheck/DCAppAttestService/generateAssertion:clientDataHash:completionHandler:``
     /// with an unattested key.
+    /// - The App Attest service cannot enforce the key access control policy on macOS.
     /// - The App Attest service rejects the key.
     DCErrorInvalidKey,
     /// An error that indicates a failed attempt to contact the App Attest service