Deprecate OS::Mac.sdk_root_needed?

[cho-m]

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
• Have you successfully run brew typecheck with your changes locally?
• Have you successfully run brew tests with your changes locally?

---

OS::Mac.sdk_root_needed? is always true now.

Need deprecation as we were using it in Homebrew/core.

[Copilot]

Pull Request Overview

This pull request deprecates the OS::Mac.sdk_root_needed? method, which now always returns true. The deprecation is necessary because the method is still being used in Homebrew/core.

• Marks OS::Mac.sdk_root_needed? as deprecated while maintaining its return value of true
• Removes conditional checks for sdk_root_needed? throughout the codebase since it's always true
• Simplifies logic in ENV setup and formula configuration by removing now-unnecessary branching

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Library/Homebrew/os/mac.rb	Adds deprecation warning to sdk_root_needed? method and updates documentation placement
Library/Homebrew/extend/os/mac/formula.rb	Removes conditional check for sdk_root_needed? when setting CMake OSX sysroot
Library/Homebrew/extend/os/mac/extend/ENV/super.rb	Simplifies build environment setup by removing sdk_root_needed? condition
Library/Homebrew/extend/os/mac/extend/ENV/std.rb	Removes sdk_root_needed? checks in SDK and libxml2 configuration
Library/Homebrew/extend/os/mac/diagnostic.rb	Removes sdk_root_needed? check from SDK availability diagnostic
Library/Homebrew/test/os/mac/diagnostic_spec.rb	Updates tests to remove mocking of sdk_root_needed? method

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

Library/Homebrew/extend/os/mac/extend/ENV/std.rb:1

• Corrected spelling of 'form' to 'from' in the comment.

# typed: true # rubocop:disable Sorbet/StrictSigil

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[p-linnane]

Do we still need this?

[MikeMcQuaid]

Good question. Worth a try but also not worth blocking PR.

[cho-m]

I left it as I wasn't sure about our policy on macOS patch releases. I hope no one is still on those versions (10.15.0 - 10.15.3) but decided to play it safe.

[MikeMcQuaid]

Thanks!