Last Green Tag First: Bisect an OSS Regression Before the Patch Review

Описание и применение

Пошаговый процесс использования последней стабильной версии как контрольной группы, проверки HEAD, и git bisect для точного выявления коммита‑причины регрессии, что сокращает ненужные изменения и ускоряет ревью.

Задача

Contributors often patch HEAD based on issue titles, leading to unnecessary changes and reviewer burden when the regression actually originates from an earlier commit.

Результат

The workflow reduces unnecessary code changes, speeds up reviews, and provides a clear, reproducible artifact (bisect log) that reviewers can replay.

Рабочий процесс

• 1. Verify the last release tag passes the oracle; if not, the issue is not a regression.
• 2. Verify HEAD fails the oracle; if not, the bug is not present.
• 3. Run git bisect with a deterministic oracle script to locate the bad commit.
• 4. Record the bisect log and add git show --stat and git tag --contains output to the PR.
• 5. Use the bisect log as evidence for reviewers to replay the test without local setup.

Доказательства

A well‑meaning contributor asked a coding model for a patch and received a thirty‑line rewrite of the process launcher.

Источник

The script below is meant to live on the topic branch, or to be pasted into the pull request body.

Источник