Guidance for finding and fixing problems in software by examining its behavior and likely causes.

Troubleshooting bugs, narrowing down causes, and choosing debugging steps.

It gives a consistent way to investigate failures instead of guessing at changes.

debugging — Cursor rule for Cursor by bernierllc

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo

git clone --depth 1 https://github.com/bernierllc/agents-environment-config

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/rules/bernierllc/agents-environment-config/debugging/github.svg)](https://agentmods.dev/rules/bernierllc/agents-environment-config/debugging)

Your own site

<a href="https://agentmods.dev/rules/bernierllc/agents-environment-config/debugging"><img src="https://agentmods.dev/badge/rules/bernierllc/agents-environment-config/debugging/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/rules/bernierllc/agents-environment-config/debugging"><img src="https://agentmods.dev/badge/rules/bernierllc/agents-environment-config/debugging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 7 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 471 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00007	$0.00471
Opus 5.5	$0.00003	$0.00188
Sonnet 5.5	$0.00001	$0.00094
Haiku 4.5	$0.00001	$0.00047

Measured 1mo ago against content hash 5d83657fc888, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

debugging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/topics/troubleshooting/debugging.mdc · 88 lines

What it actually says

Troubleshooting Standards

Error Investigation

Browser Errors

When a browser error is shared (console or copied):

Check logs: Refer to ./logs/frontend.log for frontend errors
Check console: Review browser console for errors
Check network: Review network tab for failed requests
Reproduce: Attempt to reproduce the error locally

Frontend Logs

Check logs/frontend.log for detailed error information
Review error stack traces
Check for related errors around the same time
Look for patterns in error messages

Debugging Workflow

1. Reproduce the Issue

Reproduce locally if possible
Check if issue is environment-specific
Verify steps to reproduce

2. Gather Information

Error messages and stack traces
Browser console logs
Network request logs
Server logs (if applicable)
User actions leading to error

3. Investigate Root Cause

Check code changes related to error
Review recent deployments
Check database state
Verify environment configuration

4. Fix and Verify

Implement fix
Test fix locally
Verify fix in staging
Monitor production after deployment

Common Issues

Frontend Errors

Check logs/frontend.log first
Review browser console
Check network requests
Verify API responses

Backend Errors

Check server logs
Review database logs
Check API endpoint logs
Verify error handling

Database Issues

Check connection status
Review query logs
Verify migrations
Check database state

Debugging Tools

Frontend

Browser DevTools
React DevTools
Network tab
Console logs

Backend

Server logs
Database logs
API logs
Error tracking (Sentry, etc.)

References

Error Handling: See topics/quality/error-handling.mdc
Logging: See topics/quality/logging.mdc
Observability: See topics/observability/monitoring.mdc

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago First seen · 88 lines · 7 tokens per session scan A 5d83657fc888

Subscribe to this mod's changes

debugging is a cursor rule published in the GitHub repository bernierllc/agents-environment-config (11 stars, last pushed today), licensed MIT. It adds 7 tokens to every session and 471 once invoked, about $0.0000 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Debugging errors troubleshooting

error-learning

A rule for recording errors, root-cause analyses, and bug fixes in project notes. RCA means finding the underlying reason a problem happened.

dmitryprg-ai/cursor-develop-autorules · 47 tokens

error-handling-and-validation

A code-quality guide for handling errors, invalid inputs, edge cases, preconditions, logging, and user-friendly error messages.

holtwood/awesome-cursorrules-zh · 185 tokens

css-render-blocking-diagnosis

Cursor rule "css-render-blocking-diagnosis" from adobecom/da-express-milo, covering css render-blocking diagnosis & resolution, critical learning from 98 pagespeed achievement, primary diagnostic protocol, step 1: css blocking symptom recognition and step 2: css loading sequence audit.

adobecom/da-express-milo · 1,102 tokens

debugging