macOS Computer Use service crashes while inspecting a SwiftUI sheet

Finding: In external reports on openai/codex issue 50823, Codex desktop's macOS Computer Use helper (SkyComputerUseService) crashes while reading certain SwiftUI UIs. The error is "Sky Computer Use native pipe closed before response". The original report (Codex 26.930.41038, Computer Use service 26.929.1001365, macOS 26.6.2, Apple Silicon) involved a SwiftUI sheet containing NavigationStack, ScrollView, Grid, text fields, DatePicker and Picker. It lists six crash reports with EXC_BREAKPOINT/SIGTRAP, _assertionFailure and Array.remove(at:) at the top of the faulting thread; the target app stayed usable and the reporter said resetting the tool runtime and restarting the Mac did not help (https://github.com/openai/codex/issues/50823). A later comment, on Codex app 26.1007.21159 and macOS 26.5.2, reports a small SwiftUI app with a titled GroupBox containing a TextField and a disabled Button. Reading it via cua.getApp reportedly crashed the helper repeatably, with matching frame offsets. The commenter says a first call right after launch may time out and a later read hits the crash (https://github.com/openai/codex/issues/50823#issuecomment-6089509177). Diagnostic evidence from that comment: replacing only the GroupBox with a VStack reportedly let Computer read the controls. A richer form reproduced the crash twice. The commenter also reports that keeping the GroupBox but hiding its separate title Text from accessibility and labeling the group explicitly avoided the crash in an earlier local experiment. The commenter calls this diagnostic, not a product-wide workaround. The commenter says local symbols resolve the first service frame to a UIElementTreeTransformation.transform function, but the exact invalid-index cause is not established, and the original reporter explicitly says the cause is unknown and unsymbolicated. Status: the issue is open, no maintainer response or confirmed cause is visible, and no fix commit or release is cited in the supplied sources. This is an external report; KFA did not reproduce it. Practical reading: if Computer Use crashes on a SwiftUI view containing a titled GroupBox, that construct is a reported suspect, but it is not a confirmed cause for sheets generally.