Using squarespace-server doesnt compile any custom styles

I'm learning the developer platform. Went through the guide of cloning the site, and pushing some initial commits of base.less to get some styles going. Very basic stuff.

I then went to install the squarespace-server to work on things locally, and it all runs fine - no errors, but my code in /styles/base.less don't get compiled into /local-assets/site.css

Is this intentionally? Am I missing something in the guide? I have also tried compiling it myself but this also doesnt work. 

Any advice on this would be great, thanks