| name | debug |
| description | Six-phase debugging workflow with hypothesis state persistence, structured error parsing, and git/input bisection. Use /debug to start an investigation from a failing command; /debug --resume to continue across sessions. Writes a durable log to docs/debug/<date>-<slug>.md at end. Wraps (does not replace) superpowers:systematic-debugging when that skill is installed.
|
/debug
Drives a disciplined six-phase investigation for the current project.
Reads .debug-state.json, runs the failing command, parses the
error into structured form, enumerates hypotheses (delegating to
superpowers:systematic-debugging when available), runs minimal
experiments per hypothesis, restores working-tree state between
experiments, and writes a durable debug-log artifact at end.
Usage
/debug "<failing command>" # start a fresh investigation
/debug --resume # continue from existing state
/debug --skip-isolate "<command>" # skip Phase 2 input/git bisection
/debug --yes "<command>" # don't prompt; pick first candidate
Flags
--resume — load existing .debug-state.json and resume after the
highest completed phase.--skip-isolate — skip Phase 2 (use when the failure input is
already minimal).--yes — non-interactive: auto-select the first untested hypothesis
as the candidate in Phase 3.--force — overwrite existing .debug-state.json instead of
resuming.--slug=<name> — override the auto-generated slug for the Phase 5
output path.
Pipeline
The skill runs 6 phases strictly in order. Each phase has its own file
under phases/; Read it on demand.
| Phase | File | Purpose |
|---|
| 0 | phases/0-preflight.md | git check, command presence, state init |
| 1 | phases/1-reproduce.md | run failing command, parse error to structured form |
| 2 | phases/2-isolate.md | minimise input or git bisect regression |
| 3 | phases/3-hypothesize.md | enumerate 2-3 hypotheses (wraps superpowers if available) |
| 4 | phases/4-verify.md | one experiment per candidate, restore tree between |
| 5 | phases/5-summarise.md | render debug-log.md and resolution summary |
Rules
- You orchestrate; phases are the source of truth. Read each
phase file before running it.
- State lives in
.debug-state.json. Atomic writes only. The
schema is fixed in docs/superpowers/specs/2026-05-18-harness-debug-design.md.
- Never propose a fix before Phase 1 reproduces AND Phase 3
enumerates. This is the Iron Law from
superpowers:systematic-debugging and it applies here too.
- One experiment per candidate per turn. No batch experiments;
they confound results.
- Always restore the working tree after a mutating experiment.
Verify via
restoreTo(state, stateHashBefore) — if it returns
matched: false, warn loudly and do not proceed silently.
- context-mode for any non-trivial command output. Use
mcp__plugin_context-mode_context-mode__ctx_batch_execute for
shell work where output may exceed 20 lines.
Lib modules
lib/error-parser.mjs — parseError(text, hints?) → {kind, frames[], rootException?} for 10 formats.lib/state-checkpoint.mjs — loadState/saveState/computeTreeHash/pushCheckpoint/restoreTo.lib/debug-artifacts.mjs — finishDebugSession/renderDebugLog/slugifyDebugSubject for Phase 5 state/log/index output.lib/bisector.mjs — inputBisect({input, predicate}) ddmin; gitBisect({command, knownGood, knownBad, spawn?}).lib/hypothesis-tracker.mjs — addHypothesis/decide/selectCandidate/nextUntested/summary/exportToDebugLog.lib/repro-suggester.mjs — suggestCommands({projectRoot, vague}) for Phase 0 when no command was provided.
On error
failure doesn't reproduce in Phase 1 → abort with Failure did not reproduce — environment changed?. Do NOT advance.- All hypotheses rejected and no new ones generated → loop back to
Phase 3 with a banner suggesting the failure description itself may
be wrong.
restoreTo returns matched: false after a Phase 4 experiment →
warn working tree differs from checkpoint; uncommitted experiment artifacts remain and do not auto-discard.superpowers:systematic-debugging not installed → fall back to the
inlined hypothesis prompt baked into Phase 3, with a banner saying
so.
When done (Phase 5)
Print:
Debug complete: <root-cause-one-liner>
Log: docs/debug/<date>-<slug>.md
Hypotheses: <tested>/<total> tested, <verified> verified, <rejected> rejected.
References
docs/superpowers/specs/2026-05-18-harness-debug-design.md — full design.references/integration-with-superpowers.md — how harness-debug
wraps superpowers:systematic-debugging (advisory if available).
