Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You run pip install -r requirements.txt and get a PermissionError or

You set --max-old-space-size=4096 but Node.js still crashes with a memory error. Thi...

If you see fatal: unable to access 'https://...': SSL certificate problem: unable t...

Pip Externally Managed Environment Error: Causes and Fixes
When you run pip install and get the error error: externally-managed-environme...

Nginx Upstream Connection Refused: Diagnosis and Fixes
When Nginx returns a 502 Bad Gateway or logs "upstream connection refused", it means Ngin...

How to Fix Git Detached HEAD State and Undo Changes
You run git status and see something like "HEAD detached at abc123". This ha...