Fix MacOS torch multiprocessing permission issue

[Y-T-G]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

This PR improves macOS CI reliability in ultralytics/yolov5 by adding a security-policy workaround for PyTorch multiprocessing ✅🍎

📊 Key Changes

• Added a new macOS-only step in the GitHub Actions workflow .github/workflows/ci-testing.yml.
• The new step removes the Apple quarantine attribute from the installed PyTorch package using xattr.
• It also makes PyTorch’s torch_shm_manager helper binary executable with chmod +x.
• The change is placed before the existing environment check step, so CI runs with the fix already applied.

🎯 Purpose & Impact

• Helps prevent intermittent PyTorch multiprocessing failures on macOS in CI 🛠️
• Makes automated testing more stable and consistent for contributors using macOS runners.
• Reduces flaky test failures that are caused by OS security restrictions rather than actual code issues.
• Improves confidence in CI results, making it easier to catch real bugs and avoid wasted debugging time 🚀

[UltralyticsAssistant]

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[UltralyticsAssistant]

🔍 PR Review

_{Made with ❤️ by Ultralytics Actions}

Overall clean change and well-scoped to macOS CI. One potential robustness issue: the new chmod (and import) can fail when torch_shm_manager isn’t present, which could break macOS runs.

💬 Posted 1 inline comment

[UltralyticsAssistant]

🔍 PR Review 2

_{Made with ❤️ by Ultralytics Actions}

Overall looks good and targeted to macOS CI stability. Only concern is making the chmod step resilient to torch builds that don’t include torch_shm_manager.

💬 Posted 1 inline comment

[Y-T-G]

@Laughing-q MacOS security blocks torch for some reason.

[glenn-jocher]

@Y-T-G just saw this one, merged!

[UltralyticsAssistant]

🎉 Huge thanks to @Y-T-G for this excellent contribution, with support from @glenn-jocher on getting it across the finish line!

By adding this thoughtful macOS CI workaround for PyTorch multiprocessing, you’ve helped make testing in ultralytics/yolov5 more stable, more trustworthy, and a lot less frustrating for contributors. As Thomas Edison said, “Opportunity is missed by most people because it is dressed in overalls and looks like work.” This PR is a great example of the kind of behind-the-scenes improvement that may look small at first glance, but has a big impact on reliability and developer confidence.

Really appreciate the care and practical problem-solving here — merged improvements like this make the whole project stronger 🚀