Skip to content

fix: remove flag_aliases to unbreak bazel 9#3649

Merged
rickeylev merged 1 commit intobazel-contrib:mainfrom
rickeylev:fix.rm.flag.alias
Mar 5, 2026
Merged

fix: remove flag_aliases to unbreak bazel 9#3649
rickeylev merged 1 commit intobazel-contrib:mainfrom
rickeylev:fix.rm.flag.alias

Conversation

@rickeylev
Copy link
Collaborator

The flag_alias() function in MODULE.bazel has a bug where it doesn't properly parse
labels when transitions are involved in certain ways (not entirely clear).

A fix will com in a later Bazel release. Until them, remove the calls.

Fixes #3648

@rickeylev rickeylev requested a review from aignas as a code owner March 5, 2026 07:16
@gemini-code-assist
Copy link
Contributor

Summary of Changes

Hello, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request implements a temporary workaround to address a critical compatibility issue with Bazel 9. By commenting out specific flag_alias configurations, it resolves a bug that caused build failures when these aliases were used in conjunction with transitions. This ensures that projects can continue to build successfully until a permanent fix for the flag_alias function is available in a future Bazel release.

Highlights

  • Bazel 9 Compatibility Fix: Temporarily disabled four flag_alias calls in MODULE.bazel to work around a known bug in Bazel 9 that causes parsing issues when flag_alias is used with transitions.
  • Unblocking Builds: This change resolves an issue that prevented Bazel 9 builds from succeeding, specifically addressing http://github.com/bazel-contrib/rules_python/issues/3648.

🧠 New Feature in Public Preview: You can now enable Memory to help Gemini Code Assist learn from your team's feedback. This makes future code reviews more consistent and personalized to your project's style. Click here to enable Memory in your admin console.

Changelog
  • MODULE.bazel
    • Commented out flag_alias declarations for build_python_zip, incompatible_default_to_explicit_init_py, python_path, and experimental_python_import_all_repositories.
Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature Command Description
Code Review /gemini review Performs a code review for the current pull request in its current state.
Pull Request Summary /gemini summary Provides a summary of the current pull request in its current state.
Comment @gemini-code-assist Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help /gemini help Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

  1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution.

Copy link
Contributor

@gemini-code-assist gemini-code-assist bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Code Review

This pull request addresses a build failure with Bazel 9 by temporarily disabling flag_alias calls in MODULE.bazel. The change comments out the problematic calls as a workaround for a bug in Bazel. My feedback focuses on improving the comment to ensure this temporary change is tracked and can be reverted easily in the future.

Comment on lines +463 to +464
# Temporarily comment out these flag aliases because they break Bazel 9
# when transitions are also used with a target.
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

medium

This comment provides good context. To make this temporary change easier to track and revert, consider adding a TODO with a reference to the issue. This helps ensure it's addressed once the underlying Bazel bug is fixed.

Suggested change
# Temporarily comment out these flag aliases because they break Bazel 9
# when transitions are also used with a target.
# TODO(#3648): Uncomment when the Bazel 9 bug with flag_alias is fixed.
# These are temporarily commented out to unbreak builds with transitions.

@rickeylev rickeylev added this pull request to the merge queue Mar 5, 2026
Merged via the queue into bazel-contrib:main with commit 2be0dd9 Mar 5, 2026
4 checks passed
@rickeylev rickeylev deleted the fix.rm.flag.alias branch March 5, 2026 14:49
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

Bazel 9 and transitions breaks due to flag_alias

2 participants