FRB Fix Main CI

Use this when CI is failing on the default branch (main / master) or on a commit that is already part of the default-branch history.

Choose a Path

Default-branch CI failures usually have two possible repair paths. Choose based on the evidence in the latest relevant run.

Path A: Ordinary CI Repair

Use this path when the failure looks like a known FRB CI shape: flaky job, generated diff, lint drift, stale generated output, dependency-order failure, or downstream symptom already covered by existing CI triage.

Read frb-fix-ci and repair the failure directly:

• Check the latest relevant run, not stale status.
• Use the user's tom-ci skill when reading GitHub Actions job logs.
• Classify flakes, generated diffs, lint drift, dependency-order failures, and propagated downstream symptoms before deep debugging.
• Prefer fixing prerequisite jobs such as Generate, Integrate, or high-relevance Generate Internal before chasing later build/test symptoms.

Path B: Regression Investigation

Use this path when the failure is not obviously a known FRB CI maintenance issue, or when several default-branch commits/runs suggest something recently broke.

A default-branch failure is often a regression. There should usually be an older default-branch commit that passed the same CI path. Study what changed between the green baseline and the red commit, then fix the source of that regression.

Before writing a regression fix, answer these questions:

1. What is the failing default-branch commit and workflow run?
2. What is the nearest older default-branch commit with a green run for the same workflow or job family?
3. Which commits or merged PRs sit between the green baseline and the red commit?
4. Does the failure reproduce at the red commit but not at the green baseline, using the same ./frb_internal ... command and the FRB dev environment rules?
5. Which source change most directly explains the regression?

Regression Workflow

1. Capture the exact failing jobs and the first useful error from CI logs.
2. Find the newest passing default-branch run for the same workflow/job family.
3. Compare the commit range between green and red:

bash git log --oneline --decorate <green-sha>..<red-sha> git diff --stat <green-sha>..<red-sha>

1. If the range is broad or the culprit is unclear, bisect with the smallest meaningful reproduction command.
2. Fix the source of the regression, not just the generated or downstream symptom.
3. Add or adjust regression coverage when the bug is behavioral. For pure CI/tooling drift, document the before/after evidence in the PR.

What Not To Do

• Do not treat default-branch CI as "just rerun until green" unless logs strongly indicate infra flake.
• Do not force every default-branch failure through regression bisect when frb-fix-ci already identifies a direct CI maintenance fix.
• Do not only repair checked-in generated files if the generator, template, version pin, or environment change is the real source.
• Do not chase downstream job failures while an upstream generation or integration job is still red.
• Do not assume the newest red commit is the sole cause without checking the nearest green baseline and intervening changes.

PR Expectations

For a PR that fixes default-branch CI, include:

• Failing commit SHA and workflow/job URL.
• Nearest green baseline SHA or run, if available.
• The reproduction command used locally or in Docker/Tart.
• The suspected or confirmed culprit commit/PR.
• Why the fix addresses the source of the regression.

Use frb-prepare-pr before opening the PR.