Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You're installing a package with pip, and suddenly you see a wall of red text: ERROR: C...

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...

Checklist for Troubleshooting Nginx Permission Denied Errors
Understanding the Problem
When Nginx returns a 403 Forbidden or logs an error like ...

Fixing Nginx Upstream Connection Refused and Permission Denied
If you see connect() failed (111: Connection refused) or connect() failed (13:...

Fix 'Git Remote Origin Already Exists' Without Deleting
When you run git remote add origin <url> and see fatal: remote origin al...

Fix Python Venv Not Activating in PowerShell
You open PowerShell, navigate to your project, and run venv\Scripts\activate but not...