Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You've made several edits, then checked out an old commit or tag, and now Git says you're...

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

You're browsing in Chrome and suddenly pages won't load, showing ERR_CONNECTION_R...

Fix Docker Pull Access Denied Due to Missing Credentials
If you see docker pull returning access denied with a message like ...

Fix Docker Nginx 502 Bad Gateway with MySQL
You have a Dockerized web app behind Nginx, and you're seeing a 502 Bad Gateway error. The ap...

How to Fix Nginx Redirect Loop in Server Block
You set up a server block in Nginx, but now the browser keeps redirecting—http to https, or www t...