Method
Systematic Debugging
When a bug hits, resist "change one line and see": debug in four phases — reproduce, isolate, find the root cause, then fix. Fixing symptoms does not count.
What you get
- A four-phase debugging flow
- Root-cause isolation methods
- The discipline to not guess under time pressure
Good for
- Bugs, test failures, build failures
- You have tried several fixes and none worked
- When "just change one line and see" is tempting
Not a fit
- You need completion criteria first. Use verification-before-completion
- Requirements are unclear. Use brainstorming
- You just want a feature. Build it
About this skill
You
This payment callback 500s intermittently and two fixes failed — run the four phases and find the root cause before touching code.
How to use
- Choose Copy skill and hand it to your agent.
- Reproduce and describe the symptom first — no code changes yet.
- Isolate the root cause, fix it, then verify the symptom is gone.