Getting Webpacker error: Webpacker can't find application.css

[zwfisher]

I was having trouble with .mjs files in the Uppy packages in my application so i tried cloning this repo and running it fresh. When I run rails s i get the following error:

ActionView::Template::Error (Webpacker can't find application.css in ~/code/shrine-rails-example/public/packs/manifest.json. Possible causes:
1. You want to set webpacker.yml value of compile to true for your environment
   unless you are using the `webpack -w` or the webpack-dev-server.
2. webpack has not yet re-run to reflect updates.
3. You have misconfigured Webpacker's config/webpacker.yml file.
4. Your webpack configuration is not creating a manifest.
Your manifest contains:
{
}
):
     5:     <%= csrf_meta_tags %>
     6:     <%= csp_meta_tag %>
     7:
     8:     <%= stylesheet_pack_tag 'application' %>
     9:     <%= javascript_pack_tag 'application' %>
    10:   </head>
    11:

[mikehatfield]

Don't forget to install packages during setup. For example 'yarn' It's missing from the README.

$ brew install imagemagick
$ bundle install
$ yarn
$ rake db:migrate