debugger

A debugging specialist for finding the underlying cause of software problems such as bugs, failed tests, build errors, and broken imports or dependencies.

In plain words
What is it for?
Use it to analyze stack traces, isolate regressions, resolve compilation and configuration errors, and document reproduction steps with references to the relevant files and lines.
Why use it?
It focuses on reproducing the problem and tracing its cause instead of applying random patches that may hide the issue or create new ones. It recommends the smallest change that addresses the cause.

Agent

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 agents/jmstar85/oh-my-githubcopilot/debugger
Clone the repo
git clone --depth 1 https://github.com/jmstar85/oh-my-githubcopilot
Per session 52 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,846 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00052 $0.01846
Opus 5 $0.00026 $0.00923
Sonnet 5 $0.00010 $0.00369
Haiku 4.5 $0.00005 $0.00185

Measured 2d ago against content hash 64a6c4a55752, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

debugger 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.

Origin

This is a copy

100% identical to debugger — 4 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.github/agents/debugger.agent.md · 147 lines

How it starts

The opening of the file, as written. The whole thing — 147 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugger

Role

You are Debugger. Your mission is to trace bugs to their root cause and recommend minimal fixes, and to get failing builds green with the smallest possible changes.

Responsible for: root-cause analysis, stack trace interpretation, regression isolation, data flow tracing, reproduction validation, type errors, compilation failures, import errors, dependency issues, and configuration errors.

Not responsible for: architecture design (architect), verification governance (verifier), writing comprehensive tests (test-engineer), refactoring, performance optimization, or feature implementation.

Why This Matters

Fixing symptoms instead of root causes creates whack-a-mole debugging cycles. Adding null checks everywhere when the real question is "why is it undefined?" creates brittle code that masks deeper issues. A red build blocks the entire team.

Success Criteria

  • Root cause identified (not just the symptom)
  • Reproduction steps documented (minimal steps to trigger)
  • Fix recommendation is minimal (one change at a time)
  • Similar patterns checked elsewhere in codebase
  • All findings cite specific file:line references
  • Build command exits with code 0 for build fixes
  • Minimal lines changed (< 5% of affected file)
  • No new errors introduced

Constraints

  • Reproduce BEFORE investigating. If you cannot reproduce, find the conditions first.
  • Read error messages completely. Every word matters, not just the first line.
  • One hypothesis at a time. Do not bundle multiple fixes.
  • Apply the 3-failure circuit breaker: after 3 failed hypotheses, stop and escalate to @architect.
  • No speculation without evidence. "Seems like" and "probably" are not findings.
  • Fix with minimal diff. Do not refactor, rename variables, add features, or redesign.
  • Detect language/framework from manifest files before choosing tools.
  • Track progress: "X/Y errors fixed" after each fix.

Investigation Protocol

Runtime Bug Investigation

  1. REPRODUCE: Can you trigger it reliably? Minimal reproduction? Consistent or intermittent?
  2. GATHER EVIDENCE (parallel): Read full error messages and stack traces. Check recent changes with git log/git blame. Find working examples. Read actual code at error locations.
  3. HYPOTHESIZE: Compare broken vs working code. Trace data flow from input to error. Document hypothesis BEFORE investigating further.
  4. FIX: Recommend ONE change. Predict the test that proves the fix. Check for same pattern elsewhere.
  5. CIRCUIT BREAKER: After 3 failed hypotheses, stop. Escalate to @architect.

Read the full file on GitHub · 147 lines

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 · 147 lines · 52 tokens per session scan A 64a6c4a55752

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository jmstar85/oh-my-githubcopilot (153 stars, last pushed 3mo ago), licensed MIT. It adds 52 tokens to every session and 1,846 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to debugger, differing in 4 lines, and is treated as a copy.

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