Handle missing mlx.metallib in CI pipeline

[KSemenenko]

Summary

• make the macOS staging steps resilient when the mlx.metallib asset is absent
• ensure subsequent copy operations emit warnings instead of failing the workflow

Testing

• dotnet build src/MLXSharp/MLXSharp.csproj

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https://chatgpt.com/codex/tasks/task_e_68fc9f13b5b4832685fca3d771f143dd

[Copilot]

Pull Request Overview

This PR enhances the CI workflow to gracefully handle scenarios where the mlx.metallib Metal shader library is missing from macOS native artifacts. Instead of failing the build, the workflow now emits warnings and continues execution.

• Adds conditional checks before copying mlx.metallib files
• Emits GitHub Actions warnings when the Metal library is absent
• Adds bash strict mode (set -euo pipefail) for better error handling

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[Copilot]

Adding set -euo pipefail at line 175 makes the script more strict, but the existing cp command at line 178 will still fail if libmlxsharp.dylib is missing. Consider adding a similar conditional check for the required libmlxsharp.dylib file to maintain consistency with the optional mlx.metallib handling, or document why this file's absence should cause a hard failure while mlx.metallib's absence should not.

Suggested change

	cp artifacts/native/osx-arm64/libmlxsharp.dylib src/MLXSharp/runtimes/osx-arm64/native/
	if [ -f artifacts/native/osx-arm64/libmlxsharp.dylib ]; then
	cp artifacts/native/osx-arm64/libmlxsharp.dylib src/MLXSharp/runtimes/osx-arm64/native/
	else
	echo "::error::libmlxsharp.dylib not found in macOS native artifact; cannot continue"
	exit 1
	fi

[chatgpt-codex-connector]

💡 Codex Review

MLXSharp/.github/workflows/ci.yml

Lines 221 to 223 in 42e546e

	cp artifacts/native/osx-arm64/libmlxsharp.dylib artifacts/native/
	cp artifacts/native/osx-arm64/mlx.metallib artifacts/native/
	cp artifacts/native/linux-x64/libmlxsharp.so artifacts/native/

Guard later packaging steps when metallib is missing

The earlier changes add optional handling for mlx.metallib, but the packaging stage still unconditionally copies the file and later dotnet pack commands pass it as a required parameter. When mlx.metallib is absent, the workflow will still exit with cp: cannot stat here (and the subsequent pack/verification steps would also fail), so the job remains non‑resilient to a missing metallib. Consider skipping these copies and pack arguments when the file is not present, or failing early with a clear message if the asset is required.

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