Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You try to install or run a package and get an error like package requires a different Node...

Fix Nginx 502 Bad Gateway in Docker Alpine
You have an Nginx container running on Alpine Linux, and it returns a 502 Bad Gateway. This usual...

How to Fix Nginx Redirect Loop from HTTP to HTTPS
If you're seeing an infinite redirect loop when trying to force HTTPS in nginx, the browser u...

Fix Node Sass Build Failure After npm Cache Clean
If you've run npm cache clean --force and now see a build failure related to

Fix Docker Compose Environment Variable Missing Errors
You run docker-compose up and see errors like WARNING: The VARIABLE_NAME varia...

Fixing Cloudflare 521 Error After Server Restart
You restart your server, wait for it to come back up, then visit your site—only to see a Cloudfla...