Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you see a Cloudflare 521 error page, it means Cloudflare's servers are unable to connect t...

You set a breakpoint in VS Code, run your app inside a Docker container, and the breakpoint is ne...

If you're seeing fatal: unable to access 'https://...' : Failed to connect ...:...

Python Virtual Environment Not Activating in Git Bash: Fixes
You're in Git Bash on Windows, you run source venv/Scripts/activate, and nothing...

How to Fix Git Index Lock File Exists Error
If you see an error like fatal: Unable to create 'path/to/repo/.git/index.lock': Fi...

Resolving Git Merge Conflicts in package-lock.json
If you work on a Node.js project with multiple contributors, you've likely seen a merge confl...