error compiling assets with image-url tag about sass-rails HOT 1 OPEN

I have similar issue. RAILS_ENV=production bundle exec rake assets:precompile always crash, there is no problem with development environment. After isolate scss file one by one, I realized that it crashed due to "asset-url" inside scss file.

@font-face {
  font-family: 'Source Sans Pro';
  src: asset-url('source-sans-pro-v14-latin-regular.eot');        --> this line causes crash
  ...
  font-weight: normal;
  font-style: normal;
}

I tried many ways that found by google such as

1. Downgrade sprockets from "4.0" to "3.7.2"
2. Add "env.export_concurrent = false" to initializers/assets.rb
3. Play around with Rails.application.config.assets.precompile += ....
4. ...

None of them work. Finally, I could fix it by below hack. I manually handle get method to asset files (depending on file name, then I redirect to corresponding asset file)

1. Change from "asset-url()" to "url()"
2. Update config/routes.rb by adding below code

  if Rails.env.production?
    f_redirector = lambda { |params, _req|
      _path = params[:name] + _req.path.gsub(/.*\./, '.')
      ApplicationController.helpers.asset_path(_path)
    }
    constraint = ->(request) {
      request.path.ends_with?('.eot') ||
      request.path.ends_with?('.woff') ||
      request.path.ends_with?('.ttf') ||
      request.path.ends_with?('.svg') ||
      request.path.ends_with?('.png')
    }
    get '/assets/*name', to: redirect(f_redirector), constraints: constraint
  end

This is a dirty hack, but at least my production could work temporary work for now.

from sass-rails.