Debugging Pack for Claude Code

Five skills that make Claude Code debug like a careful senior engineer. It reproduces the bug before fixing it, proves the root cause with evidence, bisects regressions to the exact commit, fixes flaky tests for good and writes the postmortem.

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Instant download: a zip with 5 skills, a setup guide and an example postmortem. The $9.99 bundle gets you all 7 kits (35 skills). Free updates. 14-day refund, no questions asked.

What's inside

Skill	What it does
`reproduce-bug`	Turns a bug report, issue or vague symptom into the smallest failing test or script, before anyone touches the fix. Checks that it fails for the reported reason, not a setup mistake.
`root-cause`	Traces a stack trace, error, log excerpt or failing test to the actual cause. Ranks hypotheses, tests each one cheaply, and only calls a cause confirmed when toggling it makes the failure appear and disappear.
`bisect-regression`	Writes an automated check script, runs `git bisect` with it, and reports the first bad commit, the hunk that broke things, and proof from reverting it.
`fix-flaky-test`	Measures the flake rate, finds the source of nondeterminism (timing, ordering, shared state, randomness, time zones, network), makes it fail every time, then fixes the cause. No retries, sleeps or skips.
`write-postmortem`	Writes a blameless postmortem from the fix, timeline, logs and commits: impact, root cause, contributing factors, detection and action items with owners. Never invents a number or a time.

What a root-cause report looks like

Example output from root-cause, given a TypeError stack trace from a login page:

Root cause (Confirmed): src/auth/session.ts:42 reads user.org.id, but invited
users have org = null until they accept. Added in a1b2c3d ("Show org name in header").

Chain: invite sent → user logs in before accepting → header renders
→ session.ts:42 → TypeError: Cannot read properties of null (reading 'id')

Evidence: repro test fails; with a null check at :42 it passes; reverting the
check makes it fail again.
Ruled out: stale cache (still fails with CACHE_DISABLED=1).

Fix options:
1. Treat org as optional at :42 (smallest change).
2. Don't create a session until the invite is accepted (closes the whole class).
Recommended: 2, with 1 as a guard.
Also affected: src/billing/plan.ts:17 makes the same assumption.

Requirements

Claude Code, with any plan or API key that runs it.
Any language or framework. The skills read your repo to learn its test runner and conventions.
Git, for bisect-regression and commit history.
Optional: the GitHub CLI (gh) to read issues, PRs and CI logs by number.

Install in two minutes

unzip debugging-pack-1.0.0.zip
mkdir -p ~/.claude/skills
cp -R debugging-pack/skills/* ~/.claude/skills/

Then say "find the root cause" with a stack trace in any repo.

License

Use and modify the skills in your own projects and inside your company, including in private repos. You can't resell or redistribute them. Full terms.