Besides code coverage, there are several execution features that can correlate with failure and thus help in localizing faults. See the talk of Marius Smytzek today 15:00 at #FSE2026: https://conf.researchr.org/details/fse-2026/fse-2026-journal-first/9/How-Execution-Features-Relate-to-Failures-An-Empirical-Study-and-Diagnosis-Approach