Rails: application.css not in asset pipeline

Question

I know this is a old question but no answer is fixing my problem.

I'm new to Ruby on Rails and just created project with a PostgreSQL database just to be able to upload the project to Heroku.

When i start the rails server im getting the error "application.css is not present in the asset pipeline."

I'm using bootstrap 4 gem and this requires that you rename the applications.css to application.scss.

I dont know what is wrong.

I really tried every answer that is on stackoverflow without any success :(

Please help me, what am i doing wrong?

This is the error im getting:

Answer 1

Ok, first thing.

Do you have config.serve_static_files = true set in your production.rb file under config/environment folder.

Since we run behind NGINX, in our case it looks like config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?

Second thing. Did you do rails assets:precompile before the uploading it to the server?

And the third thing is. Have you tried calling your file application.css.scss, and redoing the rails assets:precompile?

Last, and not least thing. How does your application.scss file look like?

Did you remove all those *= and used @import instead for Bootstrap

It is nicely described in the documentation:

Import Bootstrap styles in app/assets/stylesheets/application.scss:

// Custom bootstrap variables must be set or imported before bootstrap. @import "bootstrap";

And then it says:

Make sure the file has .scss extension (or .sass for Sass syntax). If you have just generated a new Rails app, it may come with a .css file instead. If this file exists, it will be served instead of Sass, so rename it:

$ mv app/assets/stylesheets/application.css app/assets/stylesheets/application.scss Then, remove all the *= require and *= require_tree statements from the Sass file. Instead, use @import to import Sass files.

Do not use *= require in Sass or your other stylesheets will not be able to access the Bootstrap mixins and variables.

Read more here

Answer 2

origin answer

in my case, I forgot to install yarn command in my server.

so, please install yarn before running rails server. otherwise assets:precompile will do nothing and give no warning.

update

also, make sure all of these things:

1. file exists: app/assets/stylesheets/application.css
2. its content looks like:

/* ...
 *= require_self
 *= require_tree .
 */

3. also check file app/assets/config/manifest.js,

//= link application.css