Pygmentizing your Rails app hosted on Heroku

application_helper.rb

module ApplicationHelper
  PYGMENTIZE_URL = URI.parse 'http://pygmentize.herokuapp.com/'
  def highlight_code(code, language)
    sha = Digest::SHA1.hexdigest code
    Rails.cache.fetch ['code', language, sha].join('-') do
      Net::HTTP.post_form(PYGMENTIZE_URL, lang: language, code: code).body.html_safe
    end
  end
end

heroku_error_pygments.rb.sh

Running: rake assets:precompile
rake aborted!
Could not open library '/usr/local/lib/libpython2.7.a': /usr/local/lib/libpython2.7.a: invalid ELF header
(in /tmp/build_12k2jikx5kgsi/app/assets/stylesheets/pygments.css.scss.erb)
Tasks: TOP => assets:precompile:primary
(See full trace by running task with --trace)

view.html.haml

= highlight_code "gem 'rambling-trie'", :ruby