On MacBook Pro M3 14" I can profile the Metal App performance by running it, then clicking on the M icon and choosing profile after replay. On Mac Studio M2 Ultra I cannot: the profiler starts and crashes. I have tried everything including reinstalling the OS, Xcode, the Metal SDK, you name it. The app uses the Metal 4 API. The content of the replayer errorinfo report is shown at the end. Any ideas what is going on here and/or what else I can do do root cause this and fix it? FWIW, it was worse on 26.1 (Xcode just reported Metal 4 profiling not available). In 26.2 Xcode attempts to profile and invariably crashes. === Error summary: === 1x DYErrorDomain (512) - guest app crashed (512) 1x com.apple.gputools.MTLReplayer (100) - Abort trap: 6 === First Error === Domain: DYErrorDomain Error code: 512 Description: guest app crashed (512) GTErrorKeyPID: 26913 GTErrorKeyProcessName: GPUToolsReplayService GTErrorKeyCrashDate: 2026-01-09 19:22:52 +0000 === Underlying Error #1 === Domain: com.apple.gputools.MTLReplayer Error code: 100 Description: Abort trap: 6 Call stack: 0 GPUToolsReplay 0x0000000249c25850 MakeNSError + 284 1 GPUToolsReplay 0x0000000249c26428 HandleCrashSignal + 252 2 libsystem_platform.dylib 0x00000001856c7744 _sigtramp + 56 3 libsystem_pthread.dylib 0x00000001856bd888 pthread_kill + 296 4 libsystem_c.dylib 0x00000001855c2850 abort + 124 5 libsystem_c.dylib 0x00000001855c1a84 err + 0 6 IOGPU 0x00000001a9ea60a8 -[IOGPUMetal4CommandQueue _commit:count:commitFeedback:].cold.1 + 0 7 IOGPU 0x00000001a9ea0df8 __77-[IOGPUMetal4CommandQueue commitFillArgs:count:args:argsSize:commitFeedback:]_block_invoke + 0 8 IOGPU 0x00000001a9ea1004 -[IOGPUMetal4CommandQueue _commit:count:commitFeedback:] + 148 9 AGXMetalG14X 0x00000001158a2c98 -[AGXG14XFamilyCommandQueue_mtlnext noMergeCommit:count:options:commitFeedback:error:] + 116 10 AGXMetalG14X 0x0000000115a45c14 +[AGXG14XFamilyRenderContext_mtlnext mergeRenderEncoders:count:options:commitFeedback:queue:error:] + 4740 11 AGXMetalG14X 0x00000001158a2b34 -[AGXG14XFamilyCommandQueue_mtlnext commit:count:options:] + 96 12 GPUToolsReplay 0x0000000249bf0644 GTMTLReplayController_defaultDispatchFunction_noPinning + 2744 13 GPUToolsReplay 0x0000000249befb10 GTMTLReplayController_defaultDispatchFunction + 1368 14 GPUToolsReplay 0x0000000249b7a61c _ZL16DispatchFunctionP21GTMTLReplayControllerPK11GTTraceFuncRb + 476 15 GPUToolsReplay 0x0000000249b8603c ___ZN35GTUSCSamplingStreamingManagerHelper19StreamFrameTimeDataEv_block_invoke + 456 16 Foundation 0x0000000186f6c878 __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 24 17 Foundation 0x0000000186f6c740 -[NSBlockOperation main] + 96 18 Foundation 0x0000000186f6c6d8 __NSOPERATION_IS_INVOKING_MAIN__ + 16 19 Foundation 0x0000000186f6c308 -[NSOperation start] + 640 20 Foundation 0x0000000186f6c080 __NSOPERATIONQUEUE_IS_STARTING_AN_OPERATION__ + 16 21 Foundation 0x0000000186f6bf70 __NSOQSchedule_f + 164 22 libdispatch.dylib 0x00000001855104d0 _dispatch_block_async_invoke2 + 148 23 libdispatch.dylib 0x000000018551aad4 _dispatch_client_callout + 16 24 libdispatch.dylib 0x00000001855056e4 _dispatch_continuation_pop + 596 25 libdispatch.dylib 0x0000000185504d58 _dispatch_async_redirect_invoke + 580 26 libdispatch.dylib 0x0000000185512fc8 _dispatch_root_queue_drain + 364 27 libdispatch.dylib 0x0000000185513784 _dispatch_worker_thread2 + 180 28 libsystem_pthread.dylib 0x00000001856b9e10 _pthread_wqthread + 232 29 libsystem_pthread.dylib 0x00000001856b8b9c start_wqthread + 8 Replayer breadcrumbs: [ ] GTErrorKeyProcessSignal: SIGABRT === Setup === Capture device: star.localdomain (Mac14,14) - macOS 26.2 (25C56) - 0BA10D1D-D340-5F2E-934B-536675AF9BA1 Metal version: 370.64.2 Supported graphics APIs: Metal device: Apple M2 Ultra Supported GPU families: Apple1 Apple2 Apple3 Apple4 Apple5 Apple6 Apple7 Apple8 Mac1 Mac2 Common1 Common2 Common3 Metal3 Metal4 Replay device: star (Mac14,14) - macOS 26.2 (25C56) - 0BA10D1D-D340-5F2E-934B-536675AF9BA1 Metal version: 370.64.2 Supported graphics APIs: Metal device: Apple M2 Ultra Supported GPU families: Apple1 Apple2 Apple3 Apple4 Apple5 Apple6 Apple7 Apple8 Mac1 Mac2 Common1 Common2 Common3 Metal3 Metal4 Host: Mac14,14 - macOS 26.2 (25C56) Tool: Xcode (17C52) Known SDKs:

Starting with iOS 18.0 beta 1, I've noticed that RealityKit frequently crashes in the simulator when an app launches and presents an ARView. I was able to create a small sample app with repro steps that demonstrates the issue, and I've submitted feedback: FB16144085 I've included a crash log with the feedback. If possible, I'd appreciate it if an Apple engineer could investigate and suggest a workaround. It's awkward to be restricted to the iOS 17 simulator, which does not exhibit this behavior. Please let me know if there's anything I can do to help. Thank you.

I do not understand how offline leaderboard submission is supposed to work in Game Kit: While the documentation briefly states that offline submission is supported, how is that even possible when you first have to fetch a leaderboard object in order to then call its submitScore function? How can I get the leaderboard object in the first place when offline? Can anyone enlighten me how this works? Or maybe point me to some relevant documentation?

I am trying to install the Game Porting Toolkit 2.1 according to the Readme file provided with the toolkit. When I run the following command: WINEPREFIX=~/my-game-prefix brew --prefix game-porting-toolkit/bin/wine64 winecfg I get an error message: zsh: no such file or directory: /usr/local/opt/game-porting-toolkit/bin/wine64 I don't know how to resolve this. When I type in the command which brew , I get the path /usr/local/bin/brew What am I doing wrong?

I have implemented the Game Center for authentication and saving player's game data. Both authentication and saving player's data works correctly all the time, but there is a problem with fetching and loading the data. The game works like this: At the startup, I start the authentication After the player successfully logs in, I start loading the player's data by calling fetchSavedGames method If a game data exists for the player, I receive a list of SavedGame object containing the player's data The problem is that after I uninstall the game and install it again, sometimes the SavedGame list is empty(step 3). But if I don't uninstall the game and reopen the game, this process works fine. Here's the complete code of Game Center implementation: class GameCenterHandler { public func signIn() { GKLocalPlayer.local.authenticateHandler = { viewController, error in if let viewController = viewController { viewController.present(viewController, animated: false) return } if error != nil { // Player could not be authenticated. // Disable Game Center in the game. return } // Auth successfull self.load(filename: "TestFileName") } } public func save(filename: String, data: String) { if GKLocalPlayer.local.isAuthenticated { GKLocalPlayer.local.saveGameData(Data(data.utf8), withName: filename) { savedGame, error in if savedGame != nil { // Data saved successfully } if error != nil { // Error in saving game data! } } } else { // Error in saving game data! User is not authenticated" } } public func load(filename: String) { if GKLocalPlayer.local.isAuthenticated { GKLocalPlayer.local.fetchSavedGames { games, error in if let game = games?.first(where: {$0.name == filename}){ game.loadData { data, error in if data != nil { // Data loaded successfully } if error != nil { // Error in loading game data! } } } else { // Error in loading game data! Filename not found } } } else { // Error in loading game data! User is not authenticated } } } I have also added Game Center and iCloud capabilities in xcode. Also in the iCloud section, I selected the iCloud Documents and added a container. I found a simillar question here but it doesn't make things clearer.

Hi, Introducing Swift Concurrency to my Metal app has been a bit challenging as Swift Concurrency is limited by the cooperative thread pool. GPU work is obviously not CPU bound and can block forward moving progress, especially when using waitUntilCompleted on the command buffer. For concurrent render work this has the potential of under utilizing the CPU and even creating dead locks. My question is, what is the Metal's teams general recommendation when it comes to concurrency? It seems to me that Dispatch or OperationQueues are still the preferred way for Metal bound tasks in order to gain maximum performance? To integrate with Swift Concurrency my idea is to use continuations that kick off render jobs via Dispatch or Queues? Would this be the best solution to bridge async tasks with Metal work? Thanks!

I am trying the simplest use of attachment in realityKit and get Contextual closure type @MainActor, @Sendable (inout RealityViewCameraContent) async -> void expects 1 argument, but 2 were used in closure body. Also i get cannot find Attachment in scope

I'm encountering a build failure when trying to install the Game Porting Toolkit via Homebrew. The installation fails during the game-porting-toolkit-compiler dependency build phase with a CMake compatibility error. Error Message: CMake Error at CMakeLists.txt:3 (cmake_minimum_required): Compatibility with CMake < 3.5 has been removed from CMake. Update the VERSION argument <min> value. Or, use the <min>...<max> syntax to tell CMake that the project requires at least <min> but has been updated to work with policies introduced by <max> or earlier. Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway. -- Configuring incomplete, errors occurred! Environment: macOS: 15.6.1 (Sequoia) Homebrew: 5.0.1 CMake: 3.20.2 Architecture: x86_64 (via Rosetta) Formula: apple/apple/game-porting-toolkit-compiler v0.1 Source: crossover-sources-22.1.1.tar.gz Steps to Reproduce: Install x86_64 Homebrew for Rosetta compatibility Run: arch -x86_64 /usr/local/bin/brew install apple/apple/game-porting-toolkit Build fails during dependency installation Root Cause: The LLVM/Clang sources included in crossover-sources-22.1.1.tar.gz contain a CMakeLists.txt file that specifies a minimum CMake version lower than 3.5. Modern CMake versions (3.5+) have removed backward compatibility with these older version requirements. Potential Solutions: Update the Homebrew formula to patch the CMakeLists.txt with cmake_minimum_required(VERSION 3.5) or higher Update to newer CrossOver sources with updated CMake requirements Add the -DCMAKE_POLICY_VERSION_MINIMUM=3.5 flag to the CMake build command in the formula Is this a known issue? Are there plans to update the formula or the source package to resolve this compatibility problem? Any guidance on a workaround would be appreciated. Full log available at: /Users/kentarovadney/Library/Logs/Homebrew/game-porting-toolkit-compiler/02.cmake.log Thanks for any assistance!

After authenticating the user I'm loading my Game Center leaderboards like this: let leaderboards = try await GKLeaderboard.loadLeaderboards(IDs: [leaderboardID]) This is working fine, but there are times when this just returns an empty array. When I encounter this situation, the array remains empty for several hours when retrying, but then at some point it suddenly starts working again. Is this a known issue? Or am I hitting some kind of quota maybe (as I do it quite often while developing my game)?. Edit: My leaderboards are grouped in sets if that makes any difference here.

Hello, I'm working on a game that features online multiplayer. The game is developed using Unity and Apple Unity plugins. The "isUnderAge" property restricts the online multiplayer feature. Everything works as expected on all platforms (Mac, iPhone, iPad, AppleTV, and visionPro) except on Macs equipped with an Intel chip. Using the same iCloud and GameCenter, with no restrictions enabled, "isUnderAge" returns false, as expected, but on Mac equipped with an Intel chip, it returns true. Is there any restriction or compatibility issue with those chips? Is there a workaround? Thanks

Hi, I’m testing Unity’s Spaceship HDRP demo on iPhone 17 Pro Max and iPad Pro M4 (iOS 26.1). Everything renders correctly, and my custom MetalFX Spatial plugin initializes successfully — it briefly reports active scaling (e.g. 1434×660 → 2868×1320 at 50% scaling), then reverts to native rendering a few frames later. Setup: Xcode 16.1 (targeting iOS 18) Unity 2022.3.62f3 (HDRP) Metal backend Dynamic Resolution enabled in HDRP assets and cameras Relevant Xcode console excerpt: [MetalFXPlugin] MetalFX_Enable(True) called. [SpaceshipOptions] MetalFX enabled with HDRP dynamic resolution integration. [SpaceshipOptions] Disabled TAA for MetalFX Spatial. [SpaceshipOptions] Created runtime RenderTexture: 1434x660 [MetalFX] Spatial scaler created (1434x660 → 2868x1320). [MetalFX] Processed frame with scaler. [MetalFXPlugin] Sent RenderTexture (1434x660) to MetalFX. Output target 2868x1320. [SpaceshipOptions] MetalFX target set: 1434x660 [SpaceshipOptions] Camera targetTexture cleared after MetalFX handoff. It looks like HDRP clears the camera’s target texture right after MetalFX submits the frame, which causes it to revert to native rendering. Is there a recommended way to persist or rebind the MetalFX output texture when using HDRP on iOS? Unity doesn’t appear to support MetalFX in the Editor either: Thanks!

In a Unity game, if the assetBundle.Unloadinterface is called very frequently during normal gameplay, it can cause the game application's screen to freeze, although the background music continues to play normally. This issue only occurs on iPhone 16 and iPhone 17 models, with no problems on lower-version phones. How can this problem be resolved?

在正常游戏中，如果非常频繁的调用assetBundle.Unload接口，会导致游戏应用画面卡死，但是游戏的背景音乐仍然正常播放。这类问题仅发生在iphone16 和iphone17的手机上，低版本的手机没有任何问题，请问该如何解决这个问题？

Matchmaking rules https://developer.apple.com/documentation/gamekit/matchmaking-rules?language=objc AppStoreConnectApi rules https://developer.apple.com/documentation/appstoreconnectapi/rules?language=objc ・Environment Unity 6000.2.2f1 XCode 16.1 iOS 26 3 iPhones ・AppStoreConnectApi rules "type": "gameCenterMatchmakingRuleSets", "id": "f6a88caf-85db-42bf-xxxxxxxxxxxxxxxxxxxx", "attributes": { "referenceName": "co.mygame.RuleSets.GvERandom34", "ruleLanguageVersion": 1, "minPlayers": 3, "maxPlayers": 4 }, "type": "gameCenterMatchmakingRules", "id": "6afa68ce-4d2c-496f-xxxxxxxxxxxxxxxxxxxx", "attributes": { "referenceName": "GameVersion", "description": "Check Game Version. GvERandom34", "type": "COMPATIBLE", "expression": "requests[0].properties.gameVersion == requests[1].properties.gameVersion", "weight": null }, "type": "gameCenterMatchmakingQueues", "id": "7fb645ef-4eca-4510-xxxxxxxxxxxxxxxxxxxx", "attributes": { "referenceName": "co.mygame.que.GvERandom34", "classicMatchmakingBundleIds": [] }, ・Objective-C Execution code queueName = "co.mygame.que.GvERandom34" keyStr = "gameVersion " valueStr = "1.0" - (void)MatchQueueParamStr1Start:(NSString*)queueName keyStr:(NSString*)keyStr valueStr:(NSString*)valueStr { if (@available(iOS 17.2, tvOS 17.2, macOS 14.2, visionOS 1.1, *) == NO) { DBGLOG(@"MatchQueueParamStr1Start Not support."); return; } self->_matchMakingFlag = YES; self->_matchFinishFlag = NO; self->_myMatch = nil; GKMatchRequest *req = [[GKMatchRequest alloc] init]; if (@available(iOS 17.2, tvOS 17.2, macOS 14.2, visionOS 1.1, *)) { req.queueName = queueName; req.properties = @{keyStr: valueStr}; } [[GKMatchmaker sharedMatchmaker] findMatchForRequest:req withCompletionHandler: ^(GKMatch *match, NSError *error) { if (error) { [self SetupErrorInfo:error descriptionText:@"findMatchForRequest"]; } else if(match) { self->_myMatch = match; self->_myMatch.delegate = self; } self->_matchMakingFlag = NO; self->_matchFinishFlag = YES; }]; } ・ I'm trying to match with three devices. Matching doesn't work. 5 minutes later times out. What's the problem?

The following minimal snippet SEGFAULTS with SDK 26.0 and 26.1. Won't crash if I remove async from the enclosing function signature - but it's impractical in a real project. import Metal import MetalPerformanceShaders let SEED = UInt64(0x0) typealias T = Float16 /* Why ran in async context? Because global GPU object, and async makeMTLFunction, and async makeMTLComputePipelineState. Nevertheless, can trigger the bug without using global @MainActor let myGPU = MyGPU() */ @main struct CMDLine { static func main() async { let ptr = UnsafeMutablePointer<T>.allocate(capacity: 0) async let future: Void = randomFillOnGPU(ptr, count: 0) print("Main thread is playing around") await future print("Successfully reached the end.") } static func randomFillOnGPU(_ buf: UnsafeMutablePointer<T>, count destbufcount: Int) async { // let (device, queue) = await (myGPU.device, myGPU.commandqueue) let myGPU = MyGPU() let (device, queue) = (myGPU.device, myGPU.commandqueue) // Init MTLBuffer, async let makeFunction, makeComputePipelineState, etc. let tempDataType = MPSDataType.uInt32 let randfiller = MPSMatrixRandomMTGP32(device: device, destinationDataType: tempDataType, seed: Int(bitPattern:UInt(SEED))) print("randomFillOnGPU: successfully created MPSMatrixRandom.") // try await computePipelineState // ^ Crashes before this could return // Or in this minimal case, after randomFillOnGPU() returns // make encoder, set pso, dispatch, commit... } } actor MyGPU { let device : MTLDevice let commandqueue : MTLCommandQueue init() { guard let dev: MTLDevice = MPSGetPreferredDevice(.skipRemovable), let cq = dev.makeCommandQueue(), dev.supportsFamily(.apple6) || dev.supportsFamily(.mac2) else { print("Unable to get Metal Device! Exiting"); exit(EX_UNAVAILABLE) } print("Selected device: \(String(format: "%llX", dev.registryID))") self.device = dev self.commandqueue = cq print("myGPU: initialization complete.") } } See FB20916929. Apparently objc autorelease pool is releasing the wrong address during context switch (across suspension points). I wonder why such obvious case has not been caught before.

Hi, seems MSL is missing support for a clock() shader instruction available in other graphics APIs like Vulkan or OpenGL for example.. useful for counting cost in number of clock cycles of some code insider shader with much finer granularity than launching a micro kernel with same instructions and measuring cycles cost from CPU.. also useful for MoltenVK to support that extensions.. thanks..

Hello, I am currently working on a research project under ENINCA Consulting, focused on advanced diagnostic tools for pseudorandom number generators (structural metrics, multi-seed stability, cross-architecture reproducibility, and complementary indicators to TestU01). To validate this diagnostic framework, I prototyped a small non-linear 64-bit PRNG (not as a goal in itself, but simply as a vehicle to test the methodology). During these evaluations, I observed something interesting on Apple Silicon (Mac M1): • bit-exact reproducibility between M1 ARM CPU and M1 Metal GPU, • full BigCrush pass on both CPU and Metal backends, • excellent p-values, • stable behaviour across multiple seeds and runs. This was not the intended objective, the goal was mainly to validate the diagnostic concepts, but these results raised some questions about deterministic compute behaviour in Metal. My question: Is there any official guidance on achieving (or expecting) deterministic RNG or compute behaviour across CPU ↔ Metal GPU on Apple Silicon? More specifically: • Are deterministic compute kernels expected or guaranteed on Metal for scientific workloads? • Are there recommended patterns or best practices to ensure reproducibility across GPU generations (M1 → M2 → M3 → M4)? • Are there known Metal features that can introduce non-determinism? I am not sharing the internal recurrence (this work is proprietary), but I can discuss the high-level diagnostic observations if helpful. Thank you for any insight, very interested in how the Metal engineering team views deterministic compute patterns on Apple Silicon. Pascal ENINCA Consulting

Hey I wanted to make an app that tracks changes in the room and room lightning and I was wondering if its possible to use VirtualEnvironmentProbeComponent to obtain the EnvironmentResource image and store it? If so are there any example of similar operation I could use? Thank you!

Hi, I can't see RealityKit statistics on Xcode Canvas using: arView.debugOptions = [.showStatistics] The statistics only show on a physical device, not Xcode live canvas with #Preview. Testing in Xcode 26.0.1 (17A400) on Tahoe 26.0.1 (25A362). Use case: I'm using RealityKit as a non-AR 3D engine. Xcode Canvas is useful for live iterations. Is this expected behavior? How can I see FPS on Xcode canvas? SKView for example shows all debug options on both Xcode Canvas and physical devices.

I have run into an issue where I am trying to use atomic_float in a swift package but I cannot get things to compile because it appears that the Swift Package Manager doesn't support Metal 3 (atomic_float is Metal 3 functionality). Is there any way around this? I am using // swift-tools-version: 6.1 and my Metal code includes: #include <metal_stdlib> #include <metal_geometric> #include <metal_math> #include <metal_atomic> using namespace metal; kernel void test(device atomic_float* imageBuffer [[buffer(1)]], uint id [[ thread_position_in_grid ]]) { } But I get an error on the definition of atomic_float . Any help, one more importantly, where I could have found this information about this limitation, would be helpful. -RadBobby