[MikeMcQuaid]

Avoid recommending beta Xcode releases on macOS Tahoe.

Fixes #23956

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Codex with GPT 6 Astra at Extra High effort, with local review and testing.

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[Copilot]

🟡 Changes recommended

Separate Xcode recommendations from CLT guidance and add regression coverage for Tahoe repair instructions.

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Pull request overview

Updates Xcode recommendations so macOS 26 uses Xcode 26.6 and macOS 27 uses Xcode 27.

Changes:

• Adjusts the macOS-to-Xcode version mapping.
• Updates Tahoe regression coverage.

File summaries

File	Summary
Library/Homebrew/os/mac/xcode.rb	Updates the Xcode mapping; moderate issue (2 votes) remains regarding incorrect CLT guidance on macOS 26.
Library/Homebrew/test/os/mac/xcode_spec.rb	Verifies that Tahoe recommends Xcode 26.6.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Lite (auto)

Note

Copilot is running an experiment and ran this review at Lite.

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