Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

When Nginx returns a 502 Bad Gateway or logs upstream connection refused

Fix Nginx Redirect Loop: Permanent Solutions
You're trying to reach a site, and the browser keeps bouncing between two URLs until it gives...

Fix Virtual Environment Not Activating in Terminal
Why Your Virtual Environment Won't Activate
You open a terminal, navigate to your pro...

Fix 'package.json Not Found' After Cloning a Repository
Symptom
You clone a repository from GitHub (or another remote), change into the directory...

Python Requests Timeout Not Working: Fixes & Checks
You set a timeout in requests.get(url, timeout=5), but the request hangs for minutes...

Git index.lock File Exists: Quick Fix Checklist
You try to run a Git command and see fatal: Unable to create 'path/.git/index.lock'...