Sass built app/builds/application.css not making it into header

Question

I am using the ruby Gem cssbundling-rails and dart-sass to process Sass in a Rails 7 app (and I am fairly new to Rails).

In the package.json file I define the build:css script:

"build:css": "sass ./app/assets/stylesheets/application.scss ./app/assets/builds/application.css --no-source-map --load-path=. --load-path=./node_modules --load-path=./node_modules/@rpf/sauce --load-path=app/assets/stylesheets/"

This appears to be working; I see the results of several Sass files bundled and processed into one CSS file: app/builds/application.css.

However I cannot see how to add this file to my page. We use Slim so I include the line

= stylesheet_link_tag 'application'

in the app/views/components/_head.html.slim file. That results in this fragment in the final HTML:

<link rel="stylesheet" href="/assets/application-e0cf9d8fcb18bf7f909d8d91a5e78499f82ac29523d475bf3a9ab265d5e2b451.css" />

If I load that file (application-e0cf9d8fcb18bf7f909d8d91a5e78499f82ac29523d475bf3a9ab265d5e2b451.css) into my browser I see it is an empty manifest file which starts

* This is a manifest file that'll be compiled into application.css, which will include all the files   
* listed below.  

and has no files listed below.

What am I missing? How do I load the CSS that was bundled and processed from Sass files into the app/builds/application.css file into my Slim page?

Answer 1

A simple fix is to add

link rel="stylesheet" href="/assets/application.css" type="text/css"

to app/views/components/_head.html.slim instead.