Checklists for software errors, setup, and tool workflows.

Docker Compose ENV Not Passed to Entrypoint: Fix

You define an environment variable in your docker-compose.yml, but when the containe...

Fix Cloudflare Wildcard Subdomain Not Working

If you've set up a wildcard DNS record in Cloudflare (e.g., *.example.com) but s...

Docker Nginx 502 Bad Gateway: Memory Limit Fix

You're running Nginx in Docker as a reverse proxy, and suddenly you see 502 Bad Gateway error...

Fix 'package.json Not Found' After Cloning a Repository

Symptom

You clone a repository from GitHub (or another remote), change into the directory...

Git Detached HEAD vs Attached HEAD: What It Means and How to Fix

If you've seen the message "You are in 'detached HEAD' state" while using Git...

How to Fix the Git index.lock File Exists Error

You're in the middle of a Git operation—commit, merge, or rebase—and Git stops with: fa...