Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you see fatal: unable to access 'https://...': SSL certificate problem: unable t...

Fix Docker Container Exits Immediately in Background Mode
You run a Docker container with -d (detached mode) and it exits immediately. The con...

Fix Nginx 502 Bad Gateway with Docker Environment Variables
If you see a 502 Bad Gateway from nginx running in Docker, it usually means ngin...

How to Fix Nginx 'Upstream Connection Refused' Error
When Nginx returns a 502 Bad Gateway with upstream connection refused in the error l...

Docker Compose .env File Not Loading: Common Fixes
You set environment variables in a .env file next to your docker-compose.yml

How to Fix 'Permission Denied' When Saving Files in VS Code
You're editing a file in VS Code, hit save, and get a 'permission denied' error. This...