Test failures:

flutter/flutter

• Compiling the engine on Xcode 26 for iOS fails with fatal error: 'UIUtilities/UIDefines.h' file not found #171755
• Current clang version doesn't build against the iOS 26 SDK, unknown platform 'visionos' #172335
• [Xcode 26 beta 3] Compiling the engine on macOS fails with plugin for module 'TestingMacros' not found #172155
• [ios] unit test fail on iOS 26: testFlutterPlatformViewTouchesEndedOrTouchesCancelledEventDoesNotFailTheGestureRecognizer #179907

flutter/packages

• [google_maps_flutter_ios] Fails xcodebuild analyze on Xcode 26 beta 1 #170354
• [google_maps_flutter_ios] implicit conversion from enumeration type #170440
• Pod validation fails due to warnings with Xcode 26.0 #170437
• [webview_flutter_wkwebview] Swift formatting incorrect with Xcode 26 beta 4 #172983
• webview_flutter_wkwebview tests crash during -[WKNavigationResponse dealloc] on Xcode 26 beta 4 #173326
• [webview_flutter_wkwebview] HTTPCookieProxyAPIDelegate warning Cannot explicitly specialize instance method 'map' #173744
• image_picker_ios tests crash failing on Xcode 26 beta 4: Failed due to not able to find an image with 30 seconds #173327
• [url_launcher_ios] URLLauncherUITests fail on iOS 26 #173100

Infra Issues:

• [CI] Metal toolchain is no longer bundled in Xcode and must be downloaded separately #170301
• [CI] Installing Xcode 26.0 sometimes fails when installing simulator #170355
• [CI] Xcode debug workflow doesn't work on Xcode 26 due to popup #173573
• [CI] Limit simulator tests to arm bots #170294
• [devicelab] Mac_arm64 module_test_ios fails with Xcode 26 #175905
• iOS 26.0 Simulator runtime missing on Mac_arm64 builders (Xcode 26 upgrade) #180014
• [devicelab] xcodebuild fails with "exit code 65" using Xcode 26 #179936