Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you see upstream connection refused in your Nginx error logs while using Cloudfla...

You run git pull, then git push, and get: ! [rejected] non-fast-f...

Git Merge Conflict: Keep Both Files Instead of One
When you run git merge and get a conflict, Git stops and marks the conflicting files...

Fix 'python command not found' After Windows Upgrade
After upgrading Windows 10 to 11 (or a major feature update), many users find that typing p...

Fix Nginx 502 Bad Gateway on Docker Ubuntu
You're running Nginx as a reverse proxy inside Docker on Ubuntu, and suddenly you see

Python Requests Timeout Not Waiting: Fixes and Checks
You set a timeout in Python's requests library, but the call either hangs foreve...