Checklists for software errors, setup, and tool workflows.

Fix 'git pull failed index.lock file exists' Error

When running git pull, you may see an error like:

fatal: Unable to create &#...

Python Requests Timeout Not Working: Fixes & Checks

You set a timeout in requests.get(url, timeout=5), but the request hangs for minutes...

Python Virtual Environment Not Activating on Mac: Fixes

You open Terminal, run source venv/bin/activate, and nothing happens—or you get an e...

Fix Chrome Black Screen on Nvidia GPU with Hardware Acceleration

If you're seeing a black screen in Chrome—especially when watching videos or scrolling—and yo...

Fix Nginx 502 Bad Gateway on Docker Ubuntu

You're running Nginx as a reverse proxy inside Docker on Ubuntu, and suddenly you see