Your agent (or your long day) left a big uncommitted diff and a test now fails. diffbisect tells you exactly which hunks to revert — below commit granularity, where git bisect cannot reach.
npx @precisionutilityguild/diffbisect -- npm test
- Culprits are a revert set: remove exactly these hunks and your tree passes — confirmed by an actual passing probe when the output says complete.
- Runner-agnostic: only reads exit codes (git-bisect-run convention, 125 = skip). vitest, jest, tape, ava, pytest, cargo — all fine.
- Your tree and index are never touched: every probe runs in a fresh git worktree. See the README's fresh-worktree section for the node_modules wrapper pattern.
- Honest about hard cases: interdependent hunks that exhaust the probe budget are reported as an undetermined cluster (exit 3), never as invented culprits.
Lineage: delta debugging, Zeller & Hildebrandt, IEEE TSE 2002.