investigate

Use a phased root cause investigation: gather the stack trace and logs, analyze the failing code path, form ranked hypotheses, and confirm the cause before editing. This Skill enforces that order and blocks fixes until the root cause is identified.

Root cause analysis traces a failure back to the underlying defect rather than its visible symptom. The investigate skill structures this as four phases: investigate, analyze, hypothesize, implement, with an iron law that no fix ships without a confirmed cause.

Yes. It queries prior investigations tagged for the current repository, recent project learnings, and cross-project eureka moments stored in the local gstack data directory, surfacing known patterns before re-investigating from scratch.

Pre-edit hooks run a freeze check script that enforces the debug scope boundary. This prevents premature fixes and out-of-scope changes while the root cause is still unconfirmed, reducing regressions from speculative patches.

Use it for recurring errors, regressions after deploys, and any bug where the cause is not obvious. One-line typos with known causes do not need the full workflow; intermittent or high-stakes failures do.