New Feature: --auto Flag Now Available for mach test

[Suhaib Mujahid]

Hello,

We recently landed a new feature in mach test: the --auto flag.

This allows ./mach test to use BugBug to select relevant tests to run based on your local changes. To use it, simply run:

./mach test --auto

This mirrors the behavior of ./mach try auto on the try server, which is powered by an ML model that we train on our testing data, but is now available directly in your local workflow without the need to commit or push to try.

We have also updated AGENTS.md to document this option, making it easier for AI tools to discover.

If you haven't tried it yet, we encourage you to give it a shot and share your feedback.

Thank you,

Suhaib, on behalf of the CI and Quality Tools team.