[gorset]

Selective testing is great also for smaller projects to help keep velocity high for merging and working with branches with many commits.

I implemented selective testing using bazel for a CI some years ago, and it was painful to get it right. When finished even bigger branches would only take seconds-to-minutes to go through the pipeline, which was a significant improvement from the ~30 minutes build when I started working with the project, even though the project size grew a lot.

Glad to see mill-build is prioritizing this feature.