Handle disappearing Landlock paths

[MikeMcQuaid]

• Ignore ENOENT when derived readable paths vanish during setup.
• Cover the race between command setup and Landlock application.

---

• Have you followed our Contributing guidelines?
• Have you checked for other open Pull Requests for the same change?
• Have you explained what your changes do? Performance claims (e.g. "this is faster") must include Hyperfine benchmarks.
• Have you explained why you'd like these changes included, not just what they do?
• For bug fixes, have you given step-by-step brew commands to reproduce the bug?
• Have you written new tests (excluding integration tests)? Here's an example.
• Have you successfully run brew lgtm (style, typechecking and tests) locally?

---

• I did not use AI/LLM to create this PR, or I disclosed the tool/model below and reviewed its output; I did not attribute commits to AI and will answer maintainer questions and review comments myself without AI/LLM.

OpenAI Codex 5.6 Sol xhigh with local review and (unit) testing (as on macOS).

---

[Copilot]

Pull request overview

This pull request hardens Homebrew’s Linux Landlock sandbox setup against a race where “readable” filesystem paths derived during command setup may disappear before apply! runs, causing unexpected ENOENT failures.

Changes:

• Ignore Errno::ENOENT while adding readable-path Landlock rules during apply!.
• Add an RSpec example covering the “path removed after command setup” race.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
Library/Homebrew/extend/os/linux/sandbox/landlock.rb	Rescues Errno::ENOENT when applying readable path rules so vanished paths don’t abort sandbox setup.
Library/Homebrew/test/sandbox_landlock_spec.rb	Adds a test for a readable path being removed between command and apply!.

---

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.