Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

When Nginx returns 502 Bad Gateway or logs upstream connection refused timeout...

Fix 'Permission Denied' in VS Code Terminal for Node.js
You're working in VS Code, run npm install or node app.js, and get ...

Docker Network Not Found When Running Container: Fixes
When you try to run a Docker container with --network and get an error like ne...

Fix VSCode Terminal Permission Denied in Python venv
If you see bash: /path/to/venv/bin/activate: Permission denied when trying to activa...

How to Fix Git Merge Conflict Error Code 128
When you run git merge and get error: merge conflict followed by ...

How to Manually Remove a Stuck Git index.lock File
If Git operations suddenly fail with an error like fatal: Unable to create 'path/.git/i...