Guide · Agent skill
How to use the Debugging Wizard agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
Debugging Wizard is an agent skill, a packaged set of instructions and reference notes that an AI coding agent loads when a task matches it. This guide explains what the skill changes about how the agent handles bugs, how to install it, and how to ask for help in ways that trigger it. By the end you will be able to install the skill, make a debugging request, and know what to check in the output.
Debugging WizardJeffallan/claude-skills · MIT Download the skill Quick start
- 1Download the ZIP. Download the debugging-wizard skill ZIP from the page you are reading.
- 2Unzip into a skills folder. Unzip it into ~/.claude/skills/ for personal use, or into a project's .claude/skills/ folder to limit it to that project.
- 3Or upload it in the Claude apps. Go to Settings → Capabilities → Skills and upload the ZIP.
- 4Describe the bug with evidence. Paste the full error message, stack trace, reproduction steps and any relevant logs.
- 5Let the agent reproduce and isolate. Ask it to reproduce the failure and narrow it to the smallest failing case before proposing a fix.
- 6Verify the fix and add a test. Run the code yourself to confirm the change, then ask for a regression test so the bug stays fixed.
What the debugging-wizard skill makes the agent do
With the skill installed, the agent approaches a bug as a structured investigation rather than guessing at a fix. The skill's core workflow has five steps: reproduce the problem, isolate it to the smallest failing case, form testable hypotheses and check them one at a time, implement and verify a fix, then add tests or safeguards to prevent a repeat.
The skill is also described as able to parse error messages, trace execution flow through stack traces, and correlate log entries to find where a failure started.
- Reproduce the issue before changing anything
- Gather complete error messages and stack traces
- Test one hypothesis at a time and document findings
- Add regression tests after fixing, and remove debug code before committing
Install the debugging-wizard skill
Download the skill ZIP from the page you are reading. Then choose one of two routes depending on how you use your agent.
For a personal setup, unzip the file into ~/.claude/skills/. To limit it to one project, unzip it into that project's .claude/skills/ folder. Either way, the skill folder should contain SKILL.md and the references/ folder.
If you use the Claude apps instead, upload the ZIP under Settings → Capabilities → Skills.
- Personal: ~/.claude/skills/
- Single project: .claude/skills/ inside the project
- Claude apps: Settings → Capabilities → Skills, then upload the ZIP
Trigger the skill with natural requests
You do not need a special command. The skill's description lists the situations it applies to: investigating errors, analyzing stack traces, finding root causes of unexpected behavior, troubleshooting crashes, and log analysis. Describe your problem in those terms and include the evidence you have.
Useful inputs include the full error message, the complete stack trace, the steps that cause the problem, and any relevant log lines. The skill's own rules ask for complete error messages and stack traces, so giving them up front saves a round trip.
- "Here is a stack trace from our crash on startup. Find the root cause."
- "This job fails intermittently. Help me reproduce it and narrow it down."
- "Our error rate jumped after a release. Correlate these logs and find where failures begin."
- "Find the commit that introduced this regression using git bisect."
Use the debugging tools the skill references
The skill carries reference notes on debuggers for several languages. The guide lists Node.js (node --inspect and node --inspect-brk), Python (python -m pdb and breakpoint()), Go (dlv debug) and Rust (rust-gdb or lldb). For Java, the notes point to the JDB or your IDE debugger.
The skill's examples also show a git bisect workflow for finding the first bad commit. Git must be installed for this workflow.
- Python: pdb, ipdb, or breakpoint() on Python 3.7+
- Node.js/TypeScript: node --inspect and Chrome DevTools via chrome://inspect
- Go: Delve (dlv)
- Git: required for the git bisect workflow
git bisect start
git bisect bad
git bisect good v1.2.0
# Test each checkout, then mark it good or bad
git bisect resetExample: a Python crash you can investigate
Suppose a script crashes with a traceback. Paste the full traceback and say which command runs the script. The agent should reproduce the failure, identify the line where the bad value first appears, and form a hypothesis about the cause. It can then launch the script under pdb, set a breakpoint near the failing line, and print the variables involved.
The skill's reference on common bugs lists typical causes to check, such as a null reference from a missing check or an off-by-one error in a loop bound. These are starting hypotheses to test, not conclusions.
python -m pdb script.py
# inside pdb:
# b 42 set breakpoint at line 42
# n step over
# p some_var print variableSafety notes: scripts, network and production
The skill's metadata states that it does not run scripts and does not use the network. The debugging commands it describes run on your own machine under your control, so review each command before running it.
The skill's rules say not to debug in production without safeguards, and not to leave console.log or debugger statements in committed code. Live changes carry risk, so use the skill's guidance on production systems only with the protections your team already requires.
- No scripts are bundled to run automatically, and the skill does not use the network, according to its metadata
- Review every command the agent proposes before running it
- Do not debug in production without safeguards
Tips for better results
Give the agent a way to verify. The skill expects a human or a test to confirm each fix, so state how you will check the result. Keep requests to one problem at a time, because the skill tests one change at a time and multiple simultaneous changes make results hard to read.
Ask for the output format the skill uses: Root Cause, Evidence, Fix, and Prevention.
- Include the exact error text and the command that produced it
- Say which language and version you use
- Ask for a regression test with the fix
- Use git bisect when you know a past commit worked
What people use it for
- Finding the root cause of a crash from a stack trace and its surrounding logs
- Stepping through a Python script with pdb to find where a value goes wrong
- Using git bisect to locate the commit that introduced a regression
- Correlating log entries across a failed request to find the first failure point
- Recognising common bug patterns such as race conditions, off-by-one errors and null references
Frequently asked questions
How do I install the debugging-wizard skill?
Download the ZIP from the page, then unzip it into ~/.claude/skills/ for personal use or into a project's .claude/skills/ folder for one project. In the Claude apps, you can upload the ZIP under Settings → Capabilities → Skills.
Is the debugging-wizard skill free?
The skill is published under the MIT licence, as stated on its page. Check the licence file in the repository for the full terms.
What do I need to use it?
You need an agent that supports skills. Git is required for the git bisect workflow, and you need the language debugger you plan to use, such as pdb for Python, the Node.js inspector, or delve for Go.
Does the skill run scripts or use the internet?
According to its metadata, the skill runs no scripts and uses no network. The commands it describes run on your machine, so review each one before running it.
Can it fix bugs in any language?
The skill describes itself as applying to any codebase, and its reference notes include Python, Node.js/TypeScript, Go, Rust and Java. Coverage for other languages depends on the general method rather than specific notes.
Why does the agent ask me to reproduce the bug first?
The skill's rules require reproduction before any change, because a fix that has not been tested against a reproducible failure cannot be confirmed. Giving exact steps and error output speeds this up.
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Our verdict
Use this skill if you want a disciplined, step-by-step investigation of a crash, exception, unexpected behaviour or regression, and you can run the code yourself to check results. Skip it if you need a one-click fix for a live production system or you expect the agent to verify changes without a human running the code.
Download the skill