One of my SwiftUI applications using a Canvas view started to crash with Xcode 16. It was working flawlessly with Xcode 15. I was able to come up with a minimal SwiftUI app that shows the issue:
@main struct CanvasTest: App { var body: some Scene { WindowGroup { VStack { Canvas { context, size in context.withCGContext { cgContext in let z = Int(size.width / 3.0) for i in 0..<18000 { // crashes from 17413 on cgContext.beginPath() cgContext.move(to: CGPoint(x: (i % z) * 3, y: (i / z) * 2)) cgContext.addLine(to: CGPoint(x: (i % z) * 3 + 2, y: (i / z) * 2)) cgContext.strokePath() } } } } } } }
The canvas displays 18000 lines and the context.withCGContext invocation also completes successfully. Yet, the application crashes immediately after like this (details below):
Exception Type: EXC_BREAKPOINT (SIGTRAP) Exception Codes: 0x0000000000000001, 0x00000001800eabb4 Termination Reason: SIGNAL 5 Trace/BPT trap: 5 Terminating Process: exc handler [2162]
I was wondering if anyone else noticed that change and found a way to fix it? Alternatively, I am looking for workarounds. I have to be able to display large drawings created via core context-based graphics.
Is this worth reporting to Apple?
Thanks already now for any help and advice.
Hardware Model: Mac15,9 Process: CanvasTest [2162] Path: /Users/USER/Library/Developer/CoreSimulator/Devices/0C372C7C-3D00-48AA-8124-799CB9A35C1E/data/Containers/Bundle/Application/EBAEC7A2-C93D-48B7-9754-4F3F54A33084/CanvasTest.app/CanvasTest Identifier: com.objecthub.CanvasTest Version: 1.0 (1) Code Type: ARM-64 (Native) Role: Foreground Parent Process: launchd_sim [98324] Coalition: com.apple.CoreSimulator.SimDevice.0C372C7C-3D00-48AA-8124-799CB9A35C1E [58431] Responsible Process: SimulatorTrampoline [3499] Date/Time: 2024-12-01 14:33:07.7617 +0100 Launch Time: 2024-12-01 14:33:07.4151 +0100 OS Version: macOS 15.1.1 (24B91) Release Type: User Report Version: 104 Exception Type: EXC_BREAKPOINT (SIGTRAP) Exception Codes: 0x0000000000000001, 0x00000001800eabb4 Termination Reason: SIGNAL 5 Trace/BPT trap: 5 Terminating Process: exc handler [2162] Triggered by Thread: 0 Application Specific Information: Abort Cause 268435470 Thread 0 Crashed:: Dispatch queue: com.Metal.CommandQueueDispatch 0 libxpc.dylib 0x1800eabb4 _xpc_connection_release_message.cold.1 + 60 1 libxpc.dylib 0x1800c9910 _xpc_connection_release_message + 240 2 libxpc.dylib 0x1800c80b4 _xpc_connection_enqueue + 264 3 libxpc.dylib 0x1800c8b9c xpc_connection_send_message + 128 4 MTLSimDriver 0x2275c6e7c -[MTLSimCommandQueue submitCommandBuffers:count:] + 368 5 Metal 0x19eabdfd4 -[_MTLCommandQueue _submitAvailableCommandBuffers] + 480 6 Metal 0x19eabe4ac __40-[_MTLCommandQueue submitCommandBuffer:]_block_invoke + 24 7 libdispatch.dylib 0x180178de0 _dispatch_client_callout + 16 8 libdispatch.dylib 0x180188ac8 _dispatch_lane_barrier_sync_invoke_and_complete + 92 9 Metal 0x19eabe46c -[_MTLCommandQueue submitCommandBuffer:] + 112 10 MTLSimDriver 0x2275c5fc8 -[MTLSimCommandBuffer commitAndWaitUntilSubmitted] + 40 11 RenderBox 0x1c6e9015c RB::RenderFrame::~RenderFrame() + 240 12 RenderBox 0x1c6e6e9dc __38-[RBLayer displayWithBounds:callback:]_block_invoke.27 + 500 13 libdispatch.dylib 0x180178de0 _dispatch_client_callout + 16 14 libdispatch.dylib 0x180188ac8 _dispatch_lane_barrier_sync_invoke_and_complete + 92 15 RenderBox 0x1c6e6de38 -[RBLayer displayWithBounds:callback:] + 2480 16 RenderBox 0x1c6e6d46c -[RBLayer display] + 172 17 QuartzCore 0x18b0c7e74 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 392 18 QuartzCore 0x18affca50 CA::Context::commit_transaction(CA::Transaction*, double, double*) + 464 19 QuartzCore 0x18b02b260 CA::Transaction::commit() + 652 20 UIKitCore 0x185af0f70 __34-[UIApplication _firstCommitBlock]_block_invoke_2 + 32 21 CoreFoundation 0x18041b58c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 20 22 CoreFoundation 0x18041acc4 __CFRunLoopDoBlocks + 352 23 CoreFoundation 0x1804153cc __CFRunLoopRun + 812 24 CoreFoundation 0x180414c24 CFRunLoopRunSpecific + 552 25 GraphicsServices 0x19020ab10 GSEventRunModal + 160 26 UIKitCore 0x185ad82fc -[UIApplication _run] + 796 27 UIKitCore 0x185adc4f4 UIApplicationMain + 124 28 SwiftUI 0x1d290b41c closure #1 in KitRendererCommon(_:) + 164 29 SwiftUI 0x1d290b144 runApp<A>(_:) + 84 30 SwiftUI 0x1d266bef4 static App.main() + 148 31 CanvasTest.debug.dylib 0x105061c64 static CanvasTest.$main() + 40 32 CanvasTest.debug.dylib 0x105061d14 __debug_main_executable_dylib_entry_point + 12 (CanvasTest.swift:11) 33 dyld_sim 0x10519d410 start_sim + 20 34 dyld 0x10539a274 start + 2840 Thread 4:: com.apple.uikit.eventfetch-thread 0 libsystem_kernel.dylib 0x1050f5290 mach_msg2_trap + 8 1 libsystem_kernel.dylib 0x1051066c4 mach_msg2_internal + 76 2 libsystem_kernel.dylib 0x1050fd3f4 mach_msg_overwrite + 536 3 libsystem_kernel.dylib 0x1050f55cc mach_msg + 20 4 CoreFoundation 0x18041b000 __CFRunLoopServiceMachPort + 156 5 CoreFoundation 0x180415528 __CFRunLoopRun + 1160 6 CoreFoundation 0x180414c24 CFRunLoopRunSpecific + 552 7 Foundation 0x180f319c8 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 208 8 Foundation 0x180f31be8 -[NSRunLoop(NSRunLoop) runUntilDate:] + 60 9 UIKitCore 0x185b858c0 -[UIEventFetcher threadMain] + 404 10 Foundation 0x180f58810 __NSThread__start__ + 720 11 libsystem_pthread.dylib 0x10507f6f8 _pthread_start + 104 12 libsystem_pthread.dylib 0x10507a940 thread_start + 8