Bisect narrows a history between known good and bad snapshots. Mark the behavior of the checked-out candidate, not whether its message sounds suspicious. Keep a reproducible test criterion and inspect the relevant file at each step. The first bad commit is the transition from acceptable to failing behavior within the supplied boundaries. These original fixtures provide that behavior as a changed route setting, allowing the final diagnosis to be checked without guessing a commit title. A candidate with a broken route must be marked bad even if its subject says documentation. The boundary is observed behavior. When the first bad commit is found, return to your original branch before making the repair.