Updated Xcode from 16.2 to 16.4, running Time Profile in Instruments, it launches the trace, but does not install or load on connected device, breaks the functionality. I am unable to debug... ERROR: Connection with the remote side was unexpectedly closed : <dictionary: 0x1f3c8b6d0> { count = 1, transaction: 0, voucher = 0x0, contents = "XPCErrorDescription" => <string: 0x1f3c8b850> { length = 22, contents = "Connection interrupted" } } Domain: IXRemoteErrorDomain Code: 6 User Info: { DVTErrorCreationDateKey = "2025-08-09 00:47:53 +0000"; } -- Connection with the remote side was unexpectedly closed : <dictionary: 0x1f3c8b6d0> { count = 1, transaction: 0, voucher = 0x0, contents = "XPCErrorDescription" => <string: 0x1f3c8b850> { length = 22, contents = "Connection interrupted" } } Domain: IXRemoteErrorDomain Code: 6 IOS 18.5

According to the ARM documentation for the CPU models available in Apple Silicon, the CoreSight implementation includes an Embedded Trace Macrocell which can perform a complete "Instruction Trace" (https://developer.arm.com/documentation/102119/0200/What-is-trace-). Although other operating systems such as Linux make this easy, we have not been able to find any tools or even a system-level API for accessing this feature of the ETM. In the "Instruments" window of Xcode 16+, there is a "Processor Trace" instrument, but this performs sampling and is totally unrelated to the Instruction Trace we need for debugging and analysis purposes. Because it produces a complete, contiguous sequence of branch instructions, the Instruction Trace is essential for identifying precise execution behaviors that are otherwise invisible to the developer. On other platforms, an alternative is debugger scripting, but we have found far too many bugs and reliability issues with the macOS implementation of lldb. Any suggestions would be greatly appreciated!

I tried using Create ML of Xcode 26.0 beta 7 to generate a model using the "Word Tagging" template, and I received the error: Training progress unavailable - Unexpected error. Using Create ML of XCode 16.4 with the same documentation, I was able to build the model and use it in a test app. I'd like to understand why Create ML of Xcode 26 no longer works.

Hello, I am trying to investigate my apps memory usage using the instruments tool. Whenever I attach instruments my app crashes, when I have it connected to xcode as well I can see that the crash occurs in liboainject: ___lldb_unamed_symbol117 with SIGBUS. Here's what the stack looks like. Is this a known issue? Are there any workarounds or things I can do to figure out what is causing the crash?

This is a screenshot from the Swift Task track in Xcode. I made these tasks with public actor ResourceManager { func foo() { for observer in observers { Task(name: "ResourceManager notify observers") { await notification(observer) } } } } I am confused why each of the task is showing as a separate task in the task lifetime summary. Is there a way to queue the trace in Instruments into the fact that these are indeed the same task?

I am trying to run the SwiftUI instruments tool for an iOS app and every time I run it, it either switches from giving me the "Time Profiler: Time Profiler does not support the iOS platform" error, or I end up with no data at all; however, when I run just the Time Profiler by itself it works fine. I am running this on a physical device

Enabled processor trace on my mac and other types of profiler work fine. However, Processor Trace keeps showing nothing and I see the error "Failed to stop recording session. Failed stoping ktrace session" How to solve this?

Hi :wave: I am not sure that I use it right, I was not able to profile using these events: I am on a M1 Pro machine using macOS 15.5. I just wonder if these events are support on Apple Sillicon.

I’m seeing inconsistent call stacks and usage percentages in the Time Profiler between two Instruments builds: • Xcode 16.0’s Instruments Version 16.0 (16A242d) • Xcode 16.3’s Instruments Version 16.0 (16E140) When I open an old .trace file recorded with the 16A242d profiler in the newer 16E140 Instruments, the call trees and percentage breakdowns no longer match. It looks like the latest Instruments now exposes or collapses different frames (e.g. system libraries, inline code) by default. I rely on these call stacks as a baseline to track performance regressions and verify optimizations over time. Unfortunately, every Xcode/Instruments update changes what I see, making it impossible to compare profiles across versions. My questions: Is there a way in Instruments 16.0 (16E140) to restore the exact call-tree view and percentage calculations that 16A242d produced? Failing that, is there a recommended workflow or tool for capturing CPU profiles in a way that remains stable and comparable, regardless of Xcode or Instruments version? Any guidance on achieving consistent, version-independent performance measurements would be greatly appreciated!

Hi, My name is Hani Nemati, and I work at Microsoft, where we support several macOS applications such as Microsoft Edge and Teams. I’m also the primary contributor to Microsoft Performance Tools for Apple (https://github.com/microsoft/Microsoft-Performance-Tools-Apple), an open-source project aimed at improving trace analysis across platforms. We are exploring ways to enhance our performance tracing capabilities on macOS and are particularly interested in the ability to attach PMU (Performance Monitoring Unit) counters to context switch events during trace collection. For reference, this capability is supported on Linux via LTTng using the add-context option (https://lttng.org/man/1/lttng-add-context/v2.13), and on Windows through Windows Performance Recorder (WPR), which allows PMU counters to be added at the start and end of context switches, enabling delta computation. Would it be possible to introduce similar support in Instruments for macOS? I’d appreciate any guidance or suggestions you might have on this request. Thank you, Hani Nemati Email: hanemati@microsoft

We have 2 iPhones (16 pro - iOS 18.2, 16 regular - iOS 18.5 ) in single app mode and sometimes we need to shut them down manually. After holding Power and VolumeUp, shutdown screen appears as usual, but the slider isn't responding to touch, as well as the whole screen. After force restart using volume buttons, this issue disappears, but reappears after next phone restart. If we disable single app mode -the issue is gone and touch screen works every time on shutdown screen. Both iPhones share the same behavior. Is there any other way to reliably shut down the iPhone locally without using MDM or a way to fix this issue?

Hello, I'm no macOS 26.1 I'm running through the example shown in the WWDC video "Optimizing CPU Performance with Instruments." After right-clicking a test, clicking "Profile...", and trying to run a processor trace I get the error in the subject. I have processor trace enabled on the CPU via system settings. I confirmed this by disabling it and re-enabling it and noting the error that appears when this is disabled is different from the one I'm now getting. This did previously work but I haven't tried since macOS 26 is released. Is there something new I need to be doing to my Xcode project settings in order for this to be working?

Hi everyone, I’m currently integrating AlarmKit into an app and would like to offer users the same selection of built-in iOS alarm sounds that the native Clock app provides. So far, I haven’t found any API in AlarmKit (or elsewhere in the SDK) that exposes the system’s default alarm tones. Before implementing a custom sound library, I wanted to check: Is there any way to access or present the iOS system alarm sounds when creating alarms with AlarmKit? Or are developers limited to custom audio files that we provide ourselves? If anyone has experience with AlarmKit or knows whether this is technically possible (or explicitly restricted), I’d really appreciate your insights. Thanks!

I am profiling a simple SwiftUI test app on my new iPhone through my new MacBook Pro and everything is version 26.2 (iOS, macOS, Xcode). I run Instruments with the SwiftUI template using all of the default settings and get absolutely zero data after interacting with the app for about 20 seconds. Using the Time Profiler template yields trace data. Trying the SwiftUI template again with the sample Landmarks app has the same issue as my app.

I’m reporting a severe reproducible issue in Instruments, specifically when using the SwiftUI instrument and opening Show Cause & Effect Graph. What happens: • Instruments becomes extremely laggy/unresponsive • The graph/detail area can turn solid magenta/pink • Memory usage rapidly increases (I observed around 18 GB, 25 GB, and up to 34 GB) • My Mac has crashed/restarted during this, or in other terms, had a kernel panic, where my Mac froze, and everything unresponsive. The Trackpad wouldn't even click. Important detail: • I could not find a generated kernel panic log after the crash/restart. Repro context: • SwiftUI iOS app profiled from Xcode • Trigger is specifically entering Show Cause & Effect Graph • Recordings can be short and still trigger it • Issue is much less severe or absent if I avoid that view What I already tried: • Rebooting • Short captures / fewer instruments • Clearing Xcode/Instruments caches/preferences • Retesting after cleanup • Reinstalling Xcode Is this a known Instruments regression? Is there a workaround besides avoiding Show Cause & Effect Graph? What exact diagnostics should I collect when no kernel panic file is generated? Specs: Xcode Version 26.3 (17C529) Instruments Version 26.3 (17C529) macOS Version 26.4 Beta (25E5223i) MacBook Pro 13-inch, M1, 2020, 16 GB RAM

Hi all, I've hit a reproducible issue where the presence of the SwiftUI instrument in a template prevents any data from being recorded, including from the other instruments in the same template. Removing the SwiftUI instrument immediately restores normal recording. Environment Host: macOS 26.4.1 (25E253), Mac mini Xcode / Instruments 26.4.1 (17E202) Device: iPhone 17, iOS 26.4.2 (23E261) (physical device, USB-attached) Symptom Recording the same app, same device, same session, only varying the template contents: SwiftUI template (as-is) => All lanes empty across the entire recording Same template with the SwiftUI instrument removed => Data collected normally (Time Profiler samples, Hangs, etc.) So it seems not an issue with the SwiftUI lanes specifically being empty — including the SwiftUI instrument appears to silence the entire recording. Steps to reproduce Open Instruments → pick the SwiftUI template (or build a custom template that includes the SwiftUI instrument alongside, e.g., Time Profiler). Target the device, attach to the running app. Record for ~10s, interact with the app. Stop. Result: every lane is empty. Edit the template, remove the SwiftUI instrument, re-record with no other changes. Result: normal data appears in the remaining instruments. Questions Is this a known regression in Instruments 26.4.1 on iOS 26.4.x? Is there a workaround to use the SwiftUI instrument on this OS combo (different Xcode build, runtime flag, entitlement)? Does it work for anyone on iOS 26.4.x + Xcode 26.4.1, or is everyone seeing this? I can file a Feedback if confirmed as a bug — wanted to check here first in case I'm missing a setup step. Thanks!

I was reading through this documentation about instruments command line tool https://help.apple.com/instruments/mac/current/#/devb14ffaa5 and how it can be launched from the command line. However, unlike what the documentation states, there's no such instruments command anywhere on my macos M1 (OS version 15.6). That command gives: $> instruments zsh: command not found: instruments I do have XCode installed which has the Instruments.App (GUI app) but not the command line utility: $> ls Xcode.app/Contents/Applications/ ... Instruments.app Is that linked documentation up-to-date (it does say "latest" in the URL)? Is there some other way to install this command line utility?

According to the documentation for Processor Trace, it should be available on the iPhone 16 or later. Going off of the Optimize CPU performance with Instruments WWDC session, the toggle for it should be under Developer > Performance, but I don’t see this option anywhere on my iPhone 17. I can’t run a Processor Trace in Instruments without this feature turned on, because it claims my iPhone’s CPU is unsupported. Has anyone else managed to enable Processor Trace on the A19 chips?

Instruments is crashing when the swiftui instrument is stopped (the session is finished) and the transfer begins from device to device: Crashed Thread: 11 Dispatch queue: com.apple.swiftuitracingsupport.reading Exception Type: EXC_BAD_INSTRUCTION (SIGILL) Exception Codes: 0x0000000000000001, 0x0000000000000000 Termination Reason: Namespace SIGNAL, Code 4 Illegal instruction: 4 Terminating Process: exc handler [1633] I've tried removing derived data, reinstalling xcode, updating xcode (I originally thought this might be the issue -- I needed to update to 26.2 from the 26 RC -- the update didn't fix crash or change the crash report), and restarting both devices. I'm running Instruments/Xcode 26.2 on a MacBook Pro 15" (2018) running Mac OS 15.7.2 (24G325) with an iPhone 16 Pro Max running 26.2. Hoping someone else might have seen this or could help me troubleshoot. I find the swiftui instrument be helpful and like to use it :) I can post a complete crash report as well.

I am trying to perform swiftUI instrumentation on my ios app. whenever i hit the rocord button, the app launches on target device and closes with the error: Failed to start the recording: Failed starting ktrace session. How do i resolve this please?