Uninitialized constant in Rails from Gem

Question

I am fairly new to rails and am chasing my tail trying to get a Rails app to run on my server. Locally on my Mac, everything is working fine, however when I run it on the Ubuntu server, I'm getting a NameError (uninitialized constant Api::V1::TestController::Headless) error. I have updated bundler and the relevant gems as was suggested in other posts. I am certain that Headless is in my gem file, is up to date, and is install properly. I am using Headless in with Watir Webdriver. Any suggestions on what could be causing this error would be greatly appreciated.

Ruby Version: 2.2.3

The controller in question:

class Api::V1::TestController < ApplicationController
  respond_to :json

  def index
    respond_with "test controller"
  end

  def create

    event_submit(params[:json_event])

    respond_to do |format|
      if ( @log.present? )
        format.json { render text: "Log: " + @log }
      else
        format.json { render text: "Error, no log" }
      end
    end

  end

  def nul_check(param)
    param ||= "none"
    return param
  end


  def event_submit(params)

    @log = ""

    #initialize the log
    @log = ""
    #set the browser that we will use to chrome for testing
    #use headless
    headless = Headless.new
    headless.start

    browser = Watir::browser.start 'www.google.com'

    @log += browser.title

  end

end

The Gemfile:

source 'https://rubygems.org'


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.2.4'
# Use postgresql as the database for Active Record
gem 'pg'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.1.0'

# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc

#Api gems
gem 'active_model_serializers'
gem 'deathbycaptcha'
gem 'rspec'
gem 'responders', '~> 2.0'


#Driver gems
gem 'watir-extensions-element-screenshot'
gem 'selenium-webdriver'
gem 'chromedriver-helper'
gem 'headless'
gem 'nokogiri'
gem 'watir-webdriver'

group :development, :test do
  gem 'sqlite3'
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug'
end

group :development do
  # Access an IRB console on exception pages or by using <%= console %> in views
  gem 'web-console', '~> 2.0'

  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring'
end


gem 'unicorn'

Answer 1

The problem turned out to be server ownership. The user, rails in my case, did not have ownership of the gems since I had run bundle install under my own account. A chmod for the rails user took care of the problem!