bsafronov Investigate Bug
Explain the observed failure with a mechanism that survives a meaningful attempt to distinguish it from plausible alternatives.
- Separate observations from explanations: record the triggering inputs, relevant state or event order, actual result, and expected behavior. A recent change or correlated metric is a lead, not a cause. If expected behavior itself is unsettled, identify that missing decision before classifying it as a defect.
- Trace the failing path only far enough to locate competing mechanisms. Rank hypotheses by their fit to the evidence and the cost of distinguishing them. Choose a probe whose possible results would change that ranking; vary the suspected cause while holding consequential inputs constant. Repeating the same broad failing check adds little when both explanations predict it.
- Interpret each probe against its prediction. For intermittent failures, retain the event order, state, workload, and environment that make the contrast meaningful; one clean run does not disprove a race. A reproduction, comparison, or trace must connect the proposed mechanism to the observed failure, not just show that some error occurs.
- Close with the supported mechanism, decisive evidence, and remaining uncertainty. When access or observability prevents discrimination, report the exact missing observation and how its possible results separate the live hypotheses. An untested favorite remains a hypothesis.
This outcome ends at a supported cause or a specific diagnostic blocker. Diagnosis alone does not authorize a product repair. When repair is also requested, carry its evidence into that work instead of restarting the investigation. Comparing external sources, specifying desired behavior, and requested test-first sequencing remain independently useful outcomes; none is a prerequisite here.