test_bot/formulae: only run subset of brew tests for portable Ruby

[cho-m]

Currently tests fail on all runners (Tier 1 Linux and Tier 3 macOS). It is difficult to align the setups used between Homebrew/brew and Homebrew/core so can limit to basic sanity of the cask and formula tests.

Also update brew style to run on Tier 1-only so that we don't have to manually update formula list and can keep independent from brew style implementation details.

Portable Ruby PRs have been broken for over a month now. Given we now have a new Ruby update (along with OpenSSL, etc.), this should unblock us:

• portable-ruby 4.0.6 portable-libffi 3.7.1 portable-openssl 4.0.1 homebrew-core#293046

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[Copilot]

Pull request overview

This PR adjusts test_bot’s portable Ruby workflow to avoid failures across unsupported/less-aligned runner environments by (a) restricting when brew style runs and (b) reducing the scope of brew tests executed for portable Ruby.

Changes:

• Run brew style only when Homebrew considers the current environment a “Tier 1 configuration”.
• Restrict brew tests to a subset via --only=cask,formula for portable Ruby runs.

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[MikeMcQuaid]

Why do we have tests failing on Tier 1 Linux runners? Any ideas?

[cho-m]

Currently failing on Gzip unpack test. I've tried a few changes to debug and see if chown could help:

• test/unpack_strategy: run extract with verbose #23070
• test/unpack_strategy: use Mktemp to set group #23075

Still failing on the sticky bit. I don't think we ever add it ourselves, so I'd expect the default /var/tmp sticky is causing issues in our nested directory.

Since I haven't been able to reproduce yet, I'm not able to figure out the exact conditions this happens. No issues running brew tests --only unpack_strategy/gzip on Linux VM where I spun up a Docker container (as close as I can get to CI).

[MikeMcQuaid]

Ok, thanks. Can we just skip that specific test in brew tests itself so we can run the test?

[cho-m]

Can explore again since we no longer are blocking any PRs.

I think root case is actually from running brew vendor-gems prior to tests:

brew/Library/Homebrew/dev-cmd/vendor-gems.rb

Lines 48 to 50 in df0164d

	if GitHub::Actions.env_set? && HOMEBREW_PREFIX.to_s == HOMEBREW_LINUX_DEFAULT_PREFIX
	ohai "chmod +t -R /home/linuxbrew/"
	system "sudo", "chmod", "+t", "-R", "/home/linuxbrew/"

[cho-m]

• test_bot/formulae: re-enable all tests on Tier 1 #23125

[MikeMcQuaid]

Thanks for unblocking us here @cho-m ❤️