Find Regression Commits

Identify the commit or bounded ambiguous range that changed a specific behavior from working to failing, using one reproducible oracle and isolated revision state. Do not classify setup failures as product defects or automatically revert the result.

Operating contract

• Define the exact defect and failure signature before searching history.
• Verify one known-good and one known-bad revision with the same oracle, inputs, toolchain policy, and classification rules.
• Use an isolated worktree or clean temporary clone without overwriting the user's current index/worktree.
• Classify unbuildable, missing-dependency, or infrastructure-failed revisions as skip/abort according to cause—not bad by default.
• A discovered commit is evidence for diagnosis; it does not authorize revert, blame, or compatibility work.