[Bug]: External Chrome crashes when AI launches it from the Codex sandbox on macOS 26

[agent-ptolemy]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/desktop

Steps to reproduce

1. Run T3 Code Desktop on macOS 26 with the Codex provider and the default/workspace-write sandbox.
2. Open a thread and ask the agent to interact with the external Google Chrome browser, causing browser automation to launch a new Chrome process rather than use T3's collaborative preview.
3. Observe the newly launched Chrome process terminate immediately and macOS display “Google Chrome quit unexpectedly”.
4. Retry the browser action. Each launch produces another crash report and dialog.

The affected local launches were made by a Python helper whose responsible process was T3 Code (Alpha). Chrome exited about 40 ms after launch, before a page, profile or extension could load.

Expected behavior

T3 should prevent a Codex-sandboxed process from directly launching a macOS GUI browser that cannot register with LaunchServices. It should instead:

• route the action through T3's collaborative preview/browser bridge;
• request an outside-the-sandbox launch when external Chrome is required; or
• stop before spawning Chrome and return a clear, non-retryable diagnostic.

Actual behavior

The Chrome process inherits the Codex sandbox. macOS denies its Mach service lookups to com.apple.coreservices.launchservicesd and com.apple.windowserver.active. Chrome then calls abort() while registering as a foreground application:

EXC_CRASH (SIGABRT)
Abort trap: 6

abort
___RegisterApplication_block_invoke
_RegisterApplication
TransformProcessType
ChromeMain
main

The failure occurs before browser automation establishes a transport. Automated retries create repeated native crash reports and user-facing crash dialogs.

Normal user-initiated Chrome launches work, and the Chrome bundle verifies as validly signed outside the Codex sandbox.

Impact

Major degradation or frequent failure

Version or commit

T3 Code (Alpha) 0.0.35

Environment

• macOS 26.6.2 (25G83), Apple Silicon (arm64)
• T3 Code (Alpha) 0.0.35
• Codex provider with default/workspace-write sandbox
• Google Chrome 152.0.7977.65 (arm64)

Logs or stack traces

# Sanitised macOS unified-log excerpt from one failed launch
denied lookup: name = com.apple.coreservices.launchservicesd,
requestor = Google Chrome, error = 159: Sandbox restriction

denied lookup: name = com.apple.windowserver.active,
requestor = Google Chrome, error = 159: Sandbox restriction

# Sanitised crash metadata
parentProc: Python
responsibleProc: T3 Code (Alpha)
exception: EXC_CRASH / SIGABRT
termination: Abort trap: 6
faulting thread: com.apple.main-thread

This matches the upstream Codex defect: openai/codex#30043

Screenshots, recordings, or supporting files

A screenshot of the standard macOS “Google Chrome quit unexpectedly” dialog is available, but the crash signature and sandbox denials above contain the actionable evidence. Raw .ips reports are not attached because they contain machine-specific identifiers.

Workaround

Use T3's collaborative preview instead of launching external Chrome from the Codex sandbox. If real Chrome is required, launch it outside the sandbox and attach through a supported bridge. Avoid retrying the failed launch path because every retry creates another crash dialog.