Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You mount a volume into a container, run a command that changes file ownership (e.g., chown...

Fix VS Code Breakpoint Not Hit in Express App
You set a breakpoint in your Express route handler, start debugging, and the breakpoint is never ...

Fix Nginx 502 Bad Gateway with Docker Environment Variables
If you see a 502 Bad Gateway from nginx running in Docker, it usually means ngin...

Fix Nginx Upstream Connection Refused & Upstream Not Found
When you see upstream connection refused or upstream not found in your ...

Fix Node Sass Build Failure: Environment Variable Errors
When you run npm install or a build script and see an error like Node Sass doe...

Fix Nginx Upstream Connection Refused Behind Cloudflare
If you see upstream connection refused in your Nginx error logs while using Cloudfla...