Sprockets error Sprockets::NotImplementedError: Custom asset_path helper is not implemented

Question

I am getting the following when trying to precompile my assets locally

RAILS_ENV=production bundle exec rake assets:precompile

rake aborted!
Sprockets::NotImplementedError: Custom asset_path helper is not implemented

Extend your environment context with a custom method.

    environment.context_class.class_eval do
      def asset_path(path, options = {})
      end
    end
/Users/cman/.rvm/gems/[email protected]/gems/sprockets-3.6.0/lib/sprockets/context.rb:198:in `asset_path'
/Users/cman/.rvm/gems/[email protected]/gems/sprockets-3.6.0/lib/sprockets/context.rb:218:in `font_path'
/Users/cman/.rvm/gems/[email protected]/gems/font-awesome-rails-4.6.1.0/app/assets/stylesheets/font-awesome.css.erb:15:in `_evaluate_template'

I can't for the life of me figure out why this is happening - any suggestions as how to tackle would be greatly appreciated!

Update

I am able to precompile only if I add an initializer with the following:

Rails.application.assets.context_class.class_eval do
  def asset_path(path, options = {})
    return ''
  end
end

However, if I do so, when I push to my staging environment, the glyphicons from Bootstrap have an empty path and thus don't render:

font-face{font-family:'Glyphicons Halflings';src:url("");src:url("") format("embedded-opentype"),url("") format("woff"),url("") format("truetype"),url("") 

UPDATE 2

If I modify the initializer to the below, I get a path in my precompiles bootstrap asset for glypicons, but it is not to the precompiled Glyphicon file, it's to the non compiled asset path:

Rails.application.assets.context_class.class_eval do
  def asset_path(path, options = {})
    #return ''
    "/assets/#{path}"
  end
end

@font-face{font-family:'Glyphicons Halflings';src:url("/assets/bootstrap/glyphicons-halflings-regular.eot");src:url("/assets/bootstrap/glyphicons-halflings-regular.eot?#iefix") format("embedded-opentype"),url("/assets/bootstrap/glyphicons-halflings-regular.woff") format("woff"),url("/assets/bootstrap/glyphicons-halflings-regular.ttf") format("truetype"),url("/assets/bootstrap/glyphicons-halflings-regular.svg#glyphicons_halflingsregular")

Here is my gemfile.lock as it relates to assets/sprockets gems:

bootstrap-sass (3.1.1.0)
      sass (~> 3.2)
rails (4.2.5.2)
      actionmailer (= 4.2.5.2)
      actionpack (= 4.2.5.2)
      actionview (= 4.2.5.2)
      activejob (= 4.2.5.2)
      activemodel (= 4.2.5.2)
      activerecord (= 4.2.5.2)
      activesupport (= 4.2.5.2)
      bundler (>= 1.3.0, < 2.0)
      railties (= 4.2.5.2)
      sprockets-rails
sass (3.2.19)
    sass-rails (4.0.5)
      railties (>= 4.0.0, < 5.0)
      sass (~> 3.2.2)
      sprockets (~> 2.8, < 3.0)
      sprockets-rails (~> 2.0)

Answer 1

I suggest, that the main problem is in sprockets version. in my rails 4.2.6 project i use sprockets 3.6.0, and in your Gemfile.lock snippet you use <3.0 version.

Just like an a test, you may update rails to 4.2.6 and try out fresh sprockets 3.6.0 + sprockets-rails 3.0.1 and fresh sass-rails 5.0.4 and sass 3.4.22 gem. I really do not know which one of this updates will help, but, I think it should work.

Answer 2

I don't know if this qualifies as an answer or not, but I wound up just pulling down my production Heroku repo and confirmed everything precompiled. I then slowly upgraded all my gems and everything continued to precompile properly. I guess I'll never know what caused this. Thanks to those who contributed.

Answer 3

You can easily overcome this problem. Although your current problem is more a version related problem and not sure if you bundle update properly. But there is alternative solution. Try installing the following gem:

https://github.com/petebrowne/sprockets-helpers