[MikeMcQuaid]

• Share a thread-safe opoo_once cache across warning callers.
• Reserve Landlock warnings before forking to avoid duplicate output.
• Replace the separate bottle metadata warning guard.
• Preserve deprecation errors and distinct tap locations.

Fixes #24075
Closes #24079
Closes #24069.

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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

🟢 Approval recommended

No unresolved blocking issues were identified.

Review effort: Lite
Findings: None

What changed in this PR

Deduplicates deprecation warnings while preserving distinct tap locations and disabled-method errors.

Changes:

• Adds process-local warning caching.
• Deduplicates non-auditing warnings.
• Adds coverage for caching, auditing, locations, and disabled methods.

File	Description
Library/​Homebrew/​utils/​output.rb	Caches emitted deprecation warnings.
Library/​Homebrew/​test/​utils/​output_spec.rb	Tests deduplication and exception behavior.

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