Ignore user-configured Git hooks for tap operations

[boblail]

A global core.hooksPath (e.g. set by git lfs install) breaks brew tap and brew update: Git hooks run with Homebrew's filtered PATH, which lacks git-lfs, so every tap clone and tap update fails. Pass -c core.hooksPath=/dev/null to tap and update Git operations, as package/scripts/postinstall already does for the installer. Requested in #21621; same failure mode as #4988, #7014 and https://github.com/orgs/Homebrew/discussions/5047. No other user Git configuration is bypassed, so credential helpers for private taps keep working (cf. #22774).

To reproduce:

$ git config --global core.hooksPath ~/.githooks
$ git lfs update  # installs the stock LFS hooks into ~/.githooks
$ brew tap homebrew/command-not-found
==> Tapping homebrew/command-not-found
Cloning into '/opt/homebrew/Library/Taps/homebrew/homebrew-command-not-found'...
This repository is configured for Git LFS but 'git-lfs' was not found on your path.
Error: Failure while executing; `git clone ...` exited with 2.

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• Have you successfully run brew lgtm (style, typechecking and tests) locally?

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• AI was used to generate or assist with generating this PR.

Written with Claude Code, reviewed and directed by me. Verified with a red/green RSpec cycle (the new spec reproduces the hook failure before the fix) and a manual end-to-end reproduction: brew tap of a local repository with a hostile global core.hooksPath fails on main and succeeds with this change, with the hook confirmed not to run. brew lgtm passes locally.

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🤖 Generated with Claude Code

[MikeMcQuaid]

Thanks! Looks good when 🟢

[Copilot]

Pull request overview

This PR prevents user-defined Git hooks (via core.hooksPath, commonly set by git lfs install) from running during Homebrew tap and update Git operations, avoiding failures caused by Homebrew’s sanitized PATH (e.g., missing git-lfs).

Changes:

• Prepends git -c core.hooksPath=/dev/null to Tap#git_command! and related worktree operations.
• Wraps git invocations in cmd/update.sh and cmd/update-reset.sh with the same -c core.hooksPath=/dev/null behavior.
• Updates/adds RSpec coverage to exercise the new hook-bypass behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
Library/Homebrew/tap.rb	Forces core.hooksPath to null for tap clone/fetch and worktree add operations.
Library/Homebrew/cmd/update.sh	Ensures brew update Git calls ignore core.hooksPath hooks.
Library/Homebrew/cmd/update-reset.sh	Ensures brew update-reset Git calls ignore core.hooksPath hooks.
Library/Homebrew/test/tap_spec.rb	Updates expectations for new Git args and adds a spec intended to cover hook bypassing.

Comments suppressed due to low confidence (1)

Library/Homebrew/tap.rb:726

• Same as above: this comment refers to "user-configured hooks", but the implementation forces core.hooksPath for the invocation regardless of config scope. Rewording helps avoid implying only global config is affected.

        # Ignore user-configured hooks as in `git_command!`.
        worktree_args = ["-c", "core.hooksPath=#{File::NULL}", "-C", worktree_source_tap_path, "worktree", "add"]
        worktree_args << "--quiet" if quiet

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[boblail]

Applying Copilot's suggestions...

[MikeMcQuaid]

Thanks!