Computer Use reproducibly crashes for Mac apps containing very specific SwiftUI accessibility trees

What version of the Codex App are you using (From “About Codex” dialog)?

26.611.62324

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Darwin 27.0.0 arm64 arm

What issue are you seeing?

I am building a Mac app, and I was trying to use Computer Use to have Codex be able to visually inspect the app and make UI changes.

However, Computer Use kept "crashing". Codex always called get_app_state successfully but any subsequent action like a click would fail and cause SkyComputerUseService to crash, with the logs looking like this:

Crash report filename:
~/Library/Logs/DiagnosticReports/SkyComputerUseService-2026-06-18-105817.ips

Key fields:
app_name: SkyComputerUseService
timestamp: 2026-06-18 10:58:17 +0200
app_version: 1.0
build_version: 810
bundleID: com.openai.sky.CUAService
os_version: macOS 27.0 (26A5353q)
exception: EXC_BREAKPOINT / SIGTRAP
termination: Trace/BPT trap: 5
faultingThread: 0

Relevant thread:
AXNotificationObserver for pid 87926

Observed behavior:
Computer Use successfully returned `get_app_state`, then the next interaction failed with `Computer Use is not active`. A fresh `SkyComputerUseService-*.ips` crash report appeared at the timestamp above.

I spent hours and hours painstakingly pinpointing issues together with Codex and I believe we have found the cause, which seems to be the accessibility trees that some specific SwiftUI view layouts produce. In my case, it was this:

Form {
    Section("Example") {
        Toggle("Enabled", isOn: $isEnabled)

        Stepper(value: $value, in: 0 ... 100, step: 1) {
            LabeledContent("Value", value: "\(Int(value))")
        }
    }
}

That causes Computer Use to trip up and crash. I have created a very small Swift project that I linked below that can reproduce this crash reliably. I hope this might help to find the issue in the Computer Use plugin.

PS

During this whole process, we also found another issue where Computer Use would consistently crash:

Computer Use becomes unreliable when multiple build products exist with the same app name and bundle identifier. This can happen when the same macOS app is built into multiple DerivedData locations, for example FlowDeck DerivedData, XcodeBuildMCP DerivedData, and Xcode global DerivedData.

What steps can reproduce the bug?

Project: https://github.com/SwiftedMind/codex-computer-use-crash-demo

Basically, you just have to open the project in Codex and tell it to read the readme and try to reproduce the crash by opening the app and trying to navigate to the "Repro" sidebar menu.

What is the expected behavior?

_No response_

Additional information

_No response_