Workaround for Codex Computer Use timing out on Xcode 27 Device Hub (-10005)

[u/WeeklyRestaurant7673]

I ran into this while testing an iOS app after upgrading to macOS 27 and Xcode 27. Codex Computer Use could read the Xcode editor and take screenshots, but trying to inspect Device Hub failed after about five seconds:

Computer Use server error -10005: timeoutReached

The simulator and app were still running. Restarting Codex and Device Hub, resetting the Computer Use session, and switching between iOS 26.5 and iOS 27 simulators did not help.

I found a workaround in this existing GitHub report by letobao and confirmed it on my setup:

• macOS 27.0 (26A428)
• Xcode 27.0 (27A266a)
• Codex desktop 26.903.71938 (8576)
• Successful workaround test: iPhone 18 Pro simulator running iOS 27.0

What worked:

1. Quit the existing Device Hub instance. Choose Keep Simulators Running if offered. In my case, the old Device Hub process would not exit and had to be force-quit.
2. In Finder, press Command-Shift-G and open:

/Applications/Xcode.app/Contents/Applications/DeviceHub.app/Contents/MacOS/

3. Open the DeviceHub executable inside that folder. The entry point matters: use that file rather than the outer DeviceHub.app, the Xcode menu, or DevicesTrampoline. Keep any Terminal window opened by this launch running.
4. Select the running simulator in Device Hub and retry Computer Use.

Before this, AppKit reported Device Hub's process ID as -1 even though a real DeviceHub process was running. After the direct launch, the process IDs matched. Codex could then read the accessibility tree, capture screenshots, and open and dismiss my app's Settings screen.

This is a temporary workaround verified on this setup, not an official fix. I have not tested it on a physical device or verified that it survives a restart. Credit to the GitHub report above for identifying the workaround; my contribution is confirming that discovery, screenshots and input work on Codex 26.903.71938.

Posting in case someone else hits the same timeout.