Getting uninitialized constant error from unused gem

Question

I was trying to use the Addressable gem in a specific action in Rails.

My usual practice is to include the gem in the Gemfile, and then require the module where needed.

Gemfile:

gem 'addressable'

some_controller.rb:

class SomeController < ApplicationController

  def new
    require "addressable/uri"
    current_url = Addressable::URI.parse(request.original_url)
    ....
  end

end

However, I was getting a 500 error on other actions/controllers that did not use the gem.

Error during failsafe response: uninitialized constant Addressable

Finally, I removed all the code calling addressable, but kept the entry in the gemfile, and the 500 error persists on all actions. Why would this be?

Answer 1

Not sure why you're getting that specific error, but with a gem like Addressable where you don't want an automatic require 'addressable' performed then in your Gemfile you should have:

gem 'addressable', :require => false