Homebrew assumes origin is Homebrew/brew: brew update fetches from it, and the --changed options (and so brew lgtm) compare against the merge-base with origin/HEAD. gh repo fork sets things up the other way round, with the fork as origin and Homebrew/brew as upstream, both with --clone and when run inside an existing clone. If the fork's default branch is behind, brew lgtm then checks every file changed upstream since then, without saying why.

This makes brew doctor and brew lgtm detect that layout, where origin isn't the expected repository but another remote is, and suggest renaming the remotes:

Warning: The current git origin is:

  [email protected]:HaraldNordgren/brew.git

but the `upstream` remote is:

  [email protected]:Homebrew/brew.git


With a non-standard origin, Homebrew won't update properly

and `--changed` options compare against the wrong branch.

You can solve this by renaming the remotes:

  git -C "/path/to/brew" remote rename origin fork

  git -C "/path/to/brew" remote rename upstream origin

brew lgtm shows it before running any checks, for the brew repository or an official tap. brew doctor already flagged a non-standard origin, but it suggested git remote set-url origin https://github.com/Homebrew/brew, which would replace the fork's URL, and it also reported SSH origins like [email protected]:Homebrew/brew.git as non-standard. Both are fixed here.

This replaces the earlier version of this PR, which made --changed look for the Homebrew/brew remote by URL.

How I got here

brew lgtm had been failing for me while installing formulae, before it got to any checks. My checkout had the layout gh repo fork creates: origin was my fork, whose origin/HEAD pointed at a master from August, about 1,450 commits behind, and upstream was Homebrew/brew. So --changed saw about 1,700 changed files, 54 of them shell or workflow files. brew style then needed shfmt, and because mine was outdated, ./bin/brew tried to build go from source on my macOS 12 machine and failed.

Once I realised why, I renamed my remotes so that origin is Homebrew/brew:

$ git remote -v

HaraldNordgren  [email protected]:HaraldNordgren/brew.git (fetch)

HaraldNordgren  [email protected]:HaraldNordgren/brew.git (push)

origin  [email protected]:Homebrew/brew.git (fetch)

origin  [email protected]:Homebrew/brew.git (push)

After that, brew lgtm ran cleanly without installing anything. With this change, brew lgtm would have told me what to rename straight away.

Steps to reproduce

1. In a clone of Homebrew/brew, run gh repo fork --remote (or use gh repo fork Homebrew/brew --clone), with a fork whose default branch is behind Homebrew/brew.


2. 
   git switch -c some-change upstream/main and change one Ruby file, e.g. Library/Homebrew/utils/git.rb.


3. 
   ./bin/brew lgtm checks every file changed upstream since the fork's default branch, and ./bin/brew doctor suggests git remote set-url origin https://github.com/Homebrew/brew, which would replace the fork's URL.

Changes

• 
  brew doctor: when origin isn't the expected repository but another remote is, suggest renaming the remotes rather than git remote set-url. Accept GitHub SSH URLs for origin.


• 
  brew lgtm: show the same warning for the brew repository or an official tap before running any checks.


• Add specs for both.

• [x] Have you followed our Contributing guidelines?


• [x] Have you checked for other open Pull Requests for the same change?


• [x] Have you explained what your changes do? Performance claims (e.g. "this is faster") must include brew benchmark results.


• [x] Have you explained why you'd like these changes included, not just what they do?


• [x] For bug fixes, have you given step-by-step brew commands to reproduce the bug?


• [x] Have you written new tests (excluding integration tests)? Here's an example.


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

• [x] 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.

Claude Code (Claude Opus 5.5) helped trace why brew lgtm was installing formulae and write the change and specs. The new specs fail without the change and pass with it, and brew lgtm passes locally.

Summary by CodeRabbit

• 
  Bug Fixes
  
  
  • 
    brew lgtm now checks Git origins for repositories outside taps and for core and official taps, warning when an origin does not match the expected repository.
  
  
  • Recognised equivalent GitHub SSH and HTTPS URLs are accepted as matching origins.
  
  
  • If another fetch remote matches the expected repository, the diagnostic identifies the remote and suggests making it origin; otherwise, it retains the existing guidance for correcting the origin URL.
    <!-- end of auto-generated comment: release notes by coderabbit.ai -->