The first thing after someone reported a regression bug is to find out when it broke. After finding the regression commit it’s easier to reason about the problem context and explore a new fix.

Markus Staab

Git bisect can be automated using the `git bisect run` command to find regression commits without manual intervention. The process involves creating a test script that returns exit code 0 for expected behavior and non-0 for failures, then running `git bisect run ./test.sh` to automatically identify the first bad commit. This eliminates human error and saves time compared to manually testing each commit during bisection.

Automate the process to find a regression commit

Find a regression commit in PHPStan - the old manual way

<p>Automating <code>git bisect</code> with a test script is a huge time saver, especially on large repos. It removes guesswork and quickly points to the exact commit that introduced the bug.</p>
