Instruments 27.0 beta crashes (EXC_BREAKPOINT in InstrumentsPlugIn modelers) every time a recording is stopped

Question

ManojS OP

Created 5h

Replies 1

Boosts 0

Participants 2

Environment:

macOS 27.0 beta (26A5368g)
Xcode 27 beta — Instruments 27.0 (64578.226), build 27A5209h
MacBook Pro (M1, 2020), 16 GB — MacBookPro17,1
Target: physical iPhone running an iOS app (on-device LLM inference benchmarking)

Summary: Instruments crashes reproducibly with EXC_BREAKPOINT (SIGTRAP) shortly after I stop a recording. Recording itself works — the crash occurs during the post-stop analysis phase, while the trace is being processed. This has happened multiple times today with different templates (Time Profiler, and a custom document with Power Profiler / os_signpost / Thermal State).

Steps to reproduce:

Open Instruments 27.0 beta, choose Time Profiler (or a document containing Power Profiler + os_signpost)
Target a physical iPhone and an installed app
Record for a short period, then press Stop
Instruments crashes while analyzing/importing the trace

Crash details: The crashing thread is always on the dispatch queue com.apple.dt.frame.activity, inside InstrumentsPlugIn transformer/modeler code. In one report the crashing frame is:

Thread 10 Crashed:: Dispatch queue: com.apple.dt.frame.activity 0 InstrumentsPlugIn NetworkConnectionStatsModeling.__receiveRow(cursor:writer:referenceManager:) + 920 1 InstrumentsPlugIn TransformerExecutionUnit.run(yieldBlock:) + 92 2 InstrumentsPlugIn specialized TransformerHostingModeler.populateOutputTables(_:usingObserverations:parameters:checkToYieldBlock:) + 2344

Exception Type: EXC_BREAKPOINT (SIGTRAP), esr 0xf2000001 (Breakpoint) brk 1

At crash time, sibling worker threads on the same queue were executing SystemPowerImpactModeling and ProcessSubsystemImpactModeling transformers, so the failure appears to be in the modeling pipeline that runs when the recording is finalized.

Incident identifiers from two occurrences today:

D6D2467F-8553-487C-A291-EC30C0D2846F (14:13 IST)
55017CAB-5345-4865-9695-36228B B80AA4A (18:20 IST)

Filed via Feedback Assistant as FBXXXXXXXX with full crash logs and sysdiagnose attached.

Questions:

Is this a known issue in the current Instruments 27.0 beta?
Is there a recommended workaround to record and analyze traces until a fix ships — e.g., recording headlessly with xctrace and opening the .trace in a late

Screenshot 2026-07-06 at 6.23.02 PM.png r build?

Happy to provide the .trace files or additional diagnostics. Thanks!

Answer 1

Developer Tools Engineer OP

Apple

2h

Hi there!

Thanks so much for reaching out – it's not a known issue and we'd like to gather more information so that we can fix it as soon as possible.

This appears like a crash in the modeler code related to the Power Profiler (at least that's what SystemPowerImpactModeling/ProcessSubsystemImpactModeling symbols you listed indicate). Can you confirm that this is also happening also when Power Profiler is removed?

To allow us for investigating the cause, can we please ask you for:

sysdiagnose from both host and target device, ideally captured right after you experience the crash
Crash file (open Console.app, search for Crash Logs in the sidebar, look for Instruments)
How often is that reproducing? Is it every time?

and file a report using Feedback Assistant? This should have everything to allow us fix this issue.

Thanks,

Kacper