Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you see a Cloudflare origin certificate invalid error, your browser or server is rejecting the...

You try to merge two Git branches and get this error:

fatal: refusing to merge unre...

Fix Docker Compose Environment Variable Substitution Failed
When running docker compose up, you might see errors like failed to resolve co...

Fix Git Stash Error: index.lock File Exists
You run git stash and see: fatal: Unable to create 'path/.git/index.lock&#...

Fix Nginx Redirect Loop: Permanent Solutions
You're trying to reach a site, and the browser keeps bouncing between two URLs until it gives...

Fix npm run build Failed on macOS: Common Causes and Solutions
If you're on macOS and npm run build fails, you're not alone. This command o...