Agent skill · operations · nousresearch
systematic-debugging
4-phase root cause debugging: understand bugs before fixing.
Why this skill is useful
Provides a structured approach to debugging that includes specific techniques and commands for root cause analysis, which the AI may not generate on its own.
What it needs
About 9k tokens when loaded. Last updated 2026-08-07. 226,679 stars on the source repository.
What this skill does
Systematic Debugging Overview Random fixes waste time and create new bugs. Quick patches mask underlying issues. Core principle: ALWAYS find root cause before attempting fixes. Symptom fixes are failure. Violating the letter of this process is violating the spirit of debugging. The Iron Law If you haven't completed Phase 1, you cannot propose fixes. The Feedback Loop Rule The feedback loop is the debugging work. Before reading code to build a theory, create or identify a tight command that can go red on the user's exact symptom and green when the bug is fixed. A tight loop is fast, deterministic, agent-runnable, and specific enough to catch this bug — not merely "doesn't crash". When a clean repro is hard, spend disproportionate effort building the loop. Guessing without a red-capable loop is the failure mode this skill exists to prevent. When to Use Use for ANY technical issue: Test failures Bugs in production Unexpected behavior Performance problems Build failures Integration issues Use this ESPECIALLY when: Under time pressure (emergencies make guessing tempting) "Just one quick fix" seems obvious You've already tried multiple fixes Previous fix didn't work You don't fully understand the issue Don't skip when: Issue seems simple (simple bugs have root causes too) You're in a hurry (rushing guarantees rework) Someone wants it fixed NOW (systematic is faster than thrashing) The Four Phases You MUST complete each phase before proceeding to the next. --- Phase 1: Root Cause Investigation BEFORE attempting ANY fix: 1. Read Error Messages Carefully Don't skip past errors or warnings They often contain the exact solution Read stack traces completely Note line numbers, file paths, error codes Action: Use readfile on the relevant source files. Use searchfiles to find the error string in the codebase. 2. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills nousresearch/systematic-debugging