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 npm run build Syntax Error: Common Causes and Solutions
When you run npm run build and see a syntax error, the build process stops immediate...

Fix Nginx Upstream Connection Refused in Docker
You have Nginx running, either on the host or in a container, proxying to another Docker containe...

Python Requests: Fixing Connection Timeout with Proxies
You're using the Python requests library with a proxy, and you're seeing a <...

Git Detached HEAD: Practical Checklist and Fixes
You see a message like 'You are in 'detached HEAD' state' when checking out a com...

Fix Git Push Rejected Non Fast Forward Error
You try to push your local commits to a remote repository and get: ! [rejected] —