Error Diagnosis

Analyze error messages, stack traces, and log output to diagnose root causes and suggest fixes. Use when debugging crashes, runtime errors, build failures, or unexpected behavior.

Usage

Diagnose this error: [paste error message or stack trace]

Or with context:

Diagnose: [error]. Language: [lang]. Framework: [framework]. Recent changes: [what changed].

How It Works

1. Parse — extract error type, message, file locations, line numbers from raw output
2. Classify — categorize the error (syntax, runtime, dependency, config, permission, network, OOM, etc.)
3. Trace — follow the call stack to identify the originating code vs. where the error surfaced
4. Diagnose — determine root cause using error patterns, common pitfalls, and framework-specific knowledge
5. Fix — provide actionable fix with code snippets

Supported Error Sources

• Stack traces: Python, JavaScript/Node.js, Java, Go, Rust, C/C++, Ruby, PHP
• Build errors: npm, pip, cargo, gradle, maven, webpack, vite, tsc
• Runtime errors: segfaults, OOM, deadlocks, race conditions, type errors
• Infrastructure: Docker, Kubernetes, systemd, nginx, database connection errors
• CI/CD: GitHub Actions, GitLab CI, CircleCI failure logs

Output Format

## Error Type
[Classification: e.g., "TypeError — accessing property of undefined"]

## Root Cause
[1-2 sentences explaining WHY this happened]

## Fix
[Code snippet or command to resolve]

## Prevention
[How to avoid this in the future: type check, test, lint rule, etc.]

Advanced Features

Multi-Error Analysis

Paste multiple errors — the skill identifies whether they share a root cause or are independent issues.

Regression Detection

This error started after [commit/change]. Analyze whether the change could cause this.

Environment Comparison

Works in dev, fails in prod. Error: [error]. Dev config: [config]. Prod config: [config].

Scripts

scripts/parse_stacktrace.py

Extracts structured data from raw stack traces:

python3 scripts/parse_stacktrace.py < error.log

Returns JSON with error type, message, frames (file, line, function), and suggested search queries.