Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

When cloning or pulling from a Git repository, you may see:

fatal: unable to access...

Common Causes of Nginx Configuration Test Failure
When you run nginx -t and see an error, it usually means a syntax mistake, a missing...

Git index.lock File Exists: Quick Fix Checklist
You try to run a Git command and see fatal: Unable to create 'path/.git/index.lock'...

Docker Prune Not Freeing Enough Space: Practical Fixes
You run docker system prune -a expecting a big space recovery, but the freed space i...

Fix Git SSL Certificate Error: Unable to Get Local Issuer
If you see the error fatal: unable to access 'https://...': SSL certificate problem...

Fix Docker Compose 'Port Already Allocated' for MySQL
You run docker compose up and get an error like Error: Port 3306 is already al...