Computer Use MCP fails on macOS 15.7.x because bundled SkyComputerUseClient 1.0.791 requires a newer Swift runtime

[ba0gu0]

Summary

On macOS 15.7.x, Codex Desktop can fail to expose the Computer Use MCP tools even when the plugin is enabled in ~/.codex/config.toml.

In my environment, the root cause is that the current bundled Computer Use plugin (1.0.791) crashes at startup with a missing Swift Concurrency runtime symbol:

dyld: Symbol not found: _swift_task_addPriorityEscalationHandler
Referenced from: SkyComputerUseClient
Expected in: /usr/lib/swift/libswift_Concurrency.dylib

As a result:

• mcp__computer_use__ does not appear in the model tool list.
• No usable SkyComputerUseClient mcp process stays alive.
• Other MCP tools such as browser/playwright/node/pencil can still work.

Environment

macOS: 15.7.7 (24G720)
Codex Desktop current version: 26.513.20950
Broken Computer Use plugin: 1.0.791
Broken SkyComputerUseClient Runtime Version: 26.4.0
Working Computer Use plugin: 1.0.758
Working SkyComputerUseClient Runtime Version: 26.1.0

Evidence

The failing binary:

~/.codex/computer-use/Codex Computer Use.app/.../SkyComputerUseClient
sha256: 331de2ce9a9b9dea44d548758562ef65ef069bc8b5435de39bae3d3601f01f33
Runtime Version: 26.4.0

The working binary extracted from Codex Desktop 26.422.71525:

sha256: 5730f78a652fce94965eb2e5a45a1b91f35e3a2d9e247978d3e096113e60cf6f
Runtime Version: 26.1.0

The older official package currently still downloads from:

https://persistent.oaistatic.com/codex-app-prod/Codex-darwin-arm64-26.422.71525.zip

Note: x64 builds appear not to include the computer-use plugin, including both 26.422.71525 and 26.513.20950.

Workaround

I wrote a local workaround script that:

1. Downloads or reads a local Codex-darwin-arm64-26.422.71525.zip.
2. Extracts plugins/openai-bundled/plugins/computer-use.
3. Verifies the plugin version is 1.0.758.
4. Verifies SkyComputerUseClient SHA-256.
5. Backs up and replaces:
   • /Applications/Codex.app/Contents/Resources/plugins/openai-bundled/plugins/computer-use
   • ~/.codex/computer-use
   • ~/.codex/plugins/cache/openai-bundled/computer-use/1.0.758
   • ~/.codex/.tmp/bundled-marketplaces/openai-bundled/plugins/computer-use
6. Re-signs /Applications/Codex.app with local ad-hoc signing without preserving restricted entitlements.

Usage:

download patch-codex-computer-use-758.sh

bash scripts/patch-codex-computer-use-758.sh

Or with a local zip:

bash scripts/patch-codex-computer-use-758.sh "/path/to/Codex-darwin-arm64-26.422.71525.zip"

Or with a URL:

bash scripts/patch-codex-computer-use-758.sh "https://persistent.oaistatic.com/codex-app-prod/Codex-darwin-arm64-26.422.71525.zip"

Important signing detail:

codesign --force --sign - /Applications/Codex.app

Do not preserve the original entitlements. If ad-hoc signing preserves restricted entitlements, AMFI rejects launch with:

Code has restricted entitlements, but the validation of its code signature failed.

Expected Fix

Please consider either:

• shipping a SkyComputerUseClient build compatible with macOS 15.7.x system Swift runtime, or
• bundling the needed Swift runtime libraries, or
• adding a compatibility gate so unsupported Computer Use builds do not silently remove the MCP tools.

The user-visible symptom is confusing because the plugin remains enabled, but the model never receives the Computer Use tools.