[MikeMcQuaid]

• Resolve native extensions with Gem::Platform.local so installed gems load their matching binaries on Linux and macOS.
• Preserve the portable paths when regenerating setup.rb.

Fixes #24158

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

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[Copilot]

Copilot review overview

🟡 Changes recommended

setup.rb can raise NameError when loaded without RubyGems.

Review effort: Lite
Findings: None

What changed in this PR

Updates vendored Bundler paths to use the runtime platform for native extensions.

Changes:

• Uses Gem::Platform.local for extension paths.
• Preserves dynamic paths during regeneration.
• Adds runtime-platform test coverage.
• A critical RubyGems-disabled loading issue remains unresolved.

File	Description
Library/​Homebrew/​vendor/​bundle/​bundler/​setup.rb	Uses runtime platform paths; requires a fallback when RubyGems is unavailable.
Library/​Homebrew/​test/​dev-cmd/​vendor-gems_spec.rb	Tests platform-specific extension paths.
Library/​Homebrew/​dev-cmd/​vendor-gems.rb	Preserves dynamic paths during regeneration.

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