cssbundling-rails VS sassc-ruby

See the issue I opened on Github. [EDIT: closed by DHH recently]

In the Procfile.dev that's currently generated by the cssbundling-rails and jsbundling-rails gems, we can see that they write the web process like:

The functionality comes from https://github.com/rails/jsbundling-rails and https://github.com/rails/cssbundling-rails -- both come with Rails 7 and all you have to do is generate your app with the choices you want such as -j esbuild --css tailwind.

TailwindCSS from CSS Bundling for Rails - (this post)

Maybe https://github.com/rails/cssbundling-rails does what you want? For CSS only, afaik it's perfectly fine to mix different approaches for CSS and JS within one Rails app, so you could still use importmaps for JS.

The docs at https://github.com/rails/cssbundling-rails clearly state that

Install cssbundling-rails gem.

Propshaft has a smaller scope than sprockets and requires you to rely on the js-bundling and css-bundling gems to handle the building of CSS and JS assets. Read the docs for an extensive upgrade guide.

As you may know there's also a [CSS bundling](https://github.com/rails/cssbundling-rails). However, I've only upgraded a trivial project, don't know how involved that would be.

And I don't know if this is the same issue (it seems to be) but the solution suggested there that got a lot of thumbs-ups didn't work for me.

Generated make files now properly set the platform architecture when running on Linux/aarch64 and Apple's M1 family of CPUs. This allows sassc and other non-extension C-based gems to build and install properly. (sass/sassc-ruby#231, #7132, #7133)

This sprockets setup has always worked great, but lately some serious bit-rot has set in. Over the last few years, the Sass Team has deprecated both its original ruby-based version of sass, and more recently, the libsass/sassc library in favor of dart-sass. As of this writing, I could not find any sprockets compatible versions of dart-sass. Further, as time marches on, the sassc gem is beginning to accumulate some pretty nasty bugs and inefficiencies. With no fixes on the horizon, it's time to move on.