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 &#...

Fix 'pip externally managed environment' Error for venv Setup

When creating a Python virtual environment on newer Linux distributions (e.g., Debian 12, Ubuntu ...

Find Nginx Permission Denied Error Logs and Fix Access Issues

When Nginx returns a 403 Forbidden or 500 Internal Server Error, the root cause is often a permis...

How to Check Docker Disk Space Usage

If you run Docker for a while, you may notice your disk space shrinking. Images, containers, volu...

Docker Network Not Found in Swarm Mode: Fixes & Causes

When running Docker in Swarm mode, you might see an error like network "xyz" not fo...