parallel-debugging

A debugging approach that investigates several possible causes of a bug at the same time, using quick checks to compare the evidence. It starts with the exact symptom and reproduction steps before testing hypotheses.

In plain words
What is it for?
It is for diagnosing bugs, listing testable explanations, running checks in parallel, and narrowing down the cause.
Why use it?
It avoids spending too long following one suspected cause when another explanation may be more likely.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/on-deck-society/love-stack/parallel-debugging
Any agent
npx skills add on-deck-society/love-stack --skill parallel-debugging
Clone the repo
git clone --depth 1 https://github.com/on-deck-society/love-stack

Made for: Claude Code, Codex.

Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 540 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00028 $0.00540
Opus 5 $0.00014 $0.00270
Sonnet 5 $0.00006 $0.00108
Haiku 4.5 $0.00003 $0.00054

Measured 2d ago against content hash 50dc61143ba6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

parallel-debugging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

templates/skills/parallel-debugging/SKILL.md · 49 lines

How it starts

The opening of the file, as written. The whole thing — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Parallel Debugging

When activated, help the user debug a reported issue by pursuing multiple hypotheses in parallel instead of the traditional linear "try one thing, see if it works" loop.

The Process

  1. Clarify the symptom: Ask for the exact behavior observed, the expected behavior, and the reproduction steps. Do not skip this. A vague symptom makes parallel debugging impossible because you can't score evidence against hypotheses.

  2. Generate 3-5 hypotheses: Before touching code, list the possible causes. Each hypothesis should be a concrete, testable claim. Examples:

    • "The API returns stale data because the cache TTL is longer than we think."
    • "The race condition fires when two users submit within the same 100ms window."
    • "The migration didn't run in production but did in staging."
  3. For each hypothesis, identify a cheap test: What's the single fastest check that would either rule this in or rule it out? A log statement, a database query, a git log, a test repro.

  4. Run all tests in parallel: Execute the cheap tests for every hypothesis before drawing conclusions. Do not pick a favorite and chase it to the end.

  5. Score the evidence: After all tests return, rank hypotheses by how well the evidence supports them. Eliminate the disproven ones.

  6. Narrow and repeat if needed: If no hypothesis is clearly correct, generate new ones based on what you learned.

Anti-patterns to Avoid

  • Fixating on the first hypothesis and ignoring contradicting evidence
  • Running tests sequentially when they're independent
  • Skipping the clarification step because you "already know" what's wrong
  • Confirming a hypothesis without also running tests that would disprove it

Output

For each debugging session, produce:

  • The stated symptom and reproduction
  • The 3-5 hypotheses considered
  • The test and result for each
  • The conclusion with evidence references
  • The fix (or the next round of hypotheses if not yet resolved)

When to Invoke

Read the full file on GitHub · 49 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 49 lines · 28 tokens per session scan A 50dc61143ba6

Subscribe to this mod's changes

parallel-debugging is a skill published in the GitHub repository on-deck-society/love-stack (5 stars, last pushed 4mo ago), licensed MIT. It adds 28 tokens to every session and 540 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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