Debugging Expert Skill

This skill guides the agent through a rigorous root cause analysis process, treating bugs as scientific anomalies to be investigated.

🔬 The Protocol

Phase 1: Isolation

• Reproduce: Can you trigger the bug reliably?

• Minimize: What is the smallest action that triggers it?

• Boundaries: Is it Frontend (Browser) or Backend (Server)?

• Action: Check Browser Network Tab. Request sent? Payload correct?

• Action: Check Backend Logs. Request received? Error stack trace?

Phase 2: Visibility (The "Light It Up" Strategy)

If the bug is silent (no error, but wrong result):

• Trace it: Add logging at entry (Controller), middle (Service), and exit (Mapper/DB).

• Raw Payload: Log the raw input (e.g. Map instead of POJO) to verify data integrity before binding.

• Version Check: Add a FATAL or static block log with a version number (e.g., "V1.2") to prove the code running IS the code you just wrote.

Phase 3: The "Build Hygiene" Check

CRITICAL: If code looks correct but behaves wrongly, suspect the Build.

• Clean: Manually remove target/ directories.

• Recompile: Run mvn clean package .

• Inspect: grep build logs for "ERROR" or "WARNING" that was ignored.

Phase 4: Resolution & Cleanup

• Fix: Apply the smallest effective change.

• Verify: Re-run the reproduction steps.

• Cleanup: Remove all temporary System.out.println , logs, and visual markers.

How to use

Invoke this skill when you are "stuck" or when a bug persists despite "obvious" fixes.