Pre-testing a Homebrew Core autobumped tag-and-revision formula

[rgoldberg]

Output of brew config

HOMEBREW_VERSION: 6.0.22-171-g9b93c2c
ORIGIN: https://github.com/Homebrew/brew
HEAD: 9b93c2c45d77bf41982419ac0ef3a23b8bc82d62
Last commit: 2 hours ago
Branch: main
Core tap HEAD: cff22d8dbf7abae45fc3796a81aafe52c0fe00ba
Core tap last commit: 12 minutes ago
Core tap JSON: 07 Sep 10:51 UTC
Core cask tap HEAD: 3cac7fdf0e8c34cb84831938d106210d6f450bfd
Core cask tap last commit: 15 hours ago
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_GITHUB_API_TOKEN: set
HOMEBREW_NO_ANALYTICS: set
HOMEBREW_NO_ASK: set
HOMEBREW_UPGRADE_GREEDY: set
Homebrew Ruby: 4.0.6 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.6_2/bin/ruby
CPU: 14-core 64-bit arm_brava
Clang: 21.0.0 build 2100
Git: 2.55.0 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 26.6.2-arm64
CLT: 26.6.0.0.1781586589
Xcode: 26.6
Metal Toolchain: N/A
Rosetta 2: false

Output of brew doctor

Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Some installed casks are deprecated or disabled.
You should find replacements for the following casks:
macupdater

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
    periphery

Description of issue

I want to pre-test the Homebrew Core autobumped tag-and-revision mas formula before releasing new versions of mas (including before publicly publishing the new version tag on the mas GitHub repo) to ensure that:

1. The formula works for the current mas
2. The mas code builds on all macOS GHA runners (currently macos-26, macos-26-intel, macos-15, macos-15-intel & macos-14); sometimes, the SwiftPM build system on macOS 26 arm64 doesn't catch build problems on, e.g., macOS 14 or x86_64, even if it's properly configured; versions of software might behave differently on GHA runners than locally (I've tried to minimize this with a bootstrap script, but a version could change since last tested, macOS could be a different version, etc.)

The various ways I've tried to do this all have problems, some including error messages such as:

Error: Whoops, the mas formula has its version update
pull requests automatically opened by BrewTestBot every ~3 hours!
We'd still love your contributions, though, so try another one
that is excluded from autobump list (i.e. it has 'no_autobump!'
method or 'livecheck' block with 'skip'.)

I'd prefer to do this as simply as possibly, without modifying the formula (or modifying it as little as necessary), e.g., not needing to insert no_autobump!, remove or modify the livecheck block, rename the formula, use a different repo, etc.

If this isn't simple, could some flag to facilitate this be added to brew bump-formula-pr?

Attached is an initial GHA workflow that attempts this:

test-homebrew-core-formula.yaml

Note that I've been testing various command lines locally, instead of in GHA, to speed things up. I've tried --write-only instead of --dry-run, removing --online, --strict & --verbose, additional env vars, etc.

Thanks.

[SMillerDev]

This is not really a supported configuration, nor is it one we want to support because it can easily be misunderstood. The most minimal change you can make is to change the revision of the formula and build it. It won't be done by brew tooling automatically, but it's really only a single line that needs changing.

[rgoldberg]

Thanks for the info.

I manually replaced the revision of the current Homebrew Core mas formula with the revision from current main in http://github.com/mas-cli/mas; I did not replace the tag (v7.0.0), since that wasn't mentioned. I then ran:

$ HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source --formula mas
==> Fetching downloads for: mas
✘ Formula mas (7.0.0)
Error: v7.0.0 tag should be 6c5032dc8da74668c407b76d02463eea20b732a5
but is actually 7c70ffdfd9f71a654300a78b3b627782e6abe1b4

Can I change just the command line, or must I modify the formula and/or repo?

When releasing, the revision will be for tag v8.0.0, but that tag will not yet be in http://github.com/mas-cli/mas when I test the Homebrew Core mas formula; the revision that will later be tagged with v8.0.0 will be public in the main branch of http://github.com/mas-cli/mas (so far, it's always been the same revision as main itself, not just within main).

Must I replace the url & head of "https://github.com/mas-cli/mas.git" with a file:///… URL to my local clone, and change the tag to v8.0.0, which would be in my local clone?

Or should I redirect https://github.com/mas-cli/mas.git in some networking config (I'm not familiar with how to do that)?

Or is there some other way to avoid this error without publicly publishing a tag on https://github.com/mas-cli/mas?

Thanks again.

[rgoldberg]

@SMillerDev Sorry to ping, but do you know a solution to my prior reply?

Thanks.

[edel67]

You also need to remove tag:. When both fields are present, Homebrew checks out the tag and checks that its commit matches revision:.

For the commit in your example, the temporary formula change would be:

url "https://github.com/mas-cli/mas.git",
    revision: "6c5032dc8da74668c407b76d02463eea20b732a5"
version "8.0.0-pretest"

Without the tag, Homebrew needs an explicit version because it cannot infer one from that URL. You can keep the public repository URL and use your existing source-build command with HOMEBREW_NO_INSTALL_FROM_API=1, using reinstall if mas is already installed.

There’s one catch: that version only sets Homebrew’s package version. It doesn’t change the version built into mas. Your version script uses git describe --tags, whereas the formula test expects the Homebrew version. That assertion therefore won’t match this temporary label.

This lets you check whether the commit builds, but it does not make the unchanged formula test pass. Once the release tag is published, restore tag: with its matching revision:, remove the temporary version and rerun the source build and tests.

If testing the current main is enough, brew install --HEAD mas avoids the formula edit, but doesn’t pin the same commit across runners.

This is based on reading the source; I haven’t run these builds.