LoadError Specified 'sqlite3' for database adapter? - ruby-on-rails

Question

My Gemfile looks like this:
source 'https://rubygems.org'
gem 'rails', '4.0.2'
gem 'bootstrap-sass', '2.1.0.0'
gem 'activesupport', '4.0.2'
gem 'jquery-rails', '2.0.2'
gem 'railties', '4.0.2'
gem 'sass-rails', '4.0.1'
gem 'coffee-rails', '4.0.1'
gem 'rails_12factor'
gem 'actionpack', '4.0.2'
gem 'sqlite3', '1.3.5'
group :development, :test do
gem 'rspec-rails', '2.11.0'
gem 'guard-rspec', '1.2.1'
gem 'guard-spork', '1.2.0'
gem 'childprocess', '0.3.6'
gem 'spork', '0.9.2'
end
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails', '4.0.1'
gem 'coffee-rails', '4.0.1'
gem 'uglifier', '1.2.3'
end
group :test do
gem 'capybara', '1.1.2'
gem 'factory_girl_rails', '4.1.0'
gem 'cucumber-rails', '1.2.1', :require => false
gem 'database_cleaner', '0.7.0'
# gem 'launchy', '2.1.0'
# gem 'rb-fsevent', '0.9.1', :require => false
# gem 'growl', '1.0.3'
end
group :production do
gem 'pg', '0.12.2'
end
I run bundle install and bundle update but when I visit my app locally I get this error:
Specified 'sqlite3' for database adapter, but the gem is not loaded.
Add gem 'sqlite3' to your Gemfile.
I tried bundle show sqlite3 and I get /Users/siaW/.rvm/gems/ruby-2.0.0-p247#railstutorial_rails_4_0/gems/sqlite3-1.3.5 which means I do have the Gem right?
So why isn't it loading?
In my database.yml I have this:
# SQLite version 3.x
# gem install sqlite3
#
# Ensure the SQLite 3 gem is defined in your Gemfile
# gem 'sqlite3'
development:
adapter: sqlite3
database: db/development.sqlite3
pool: 5
timeout: 5000
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
production:
adapter: sqlite3
database: db/production.sqlite3
pool: 5
timeout: 5000

Answer 1

I think you may try this:
Go into your Gemfile.lock file and search for the 'sqlite3' entry. You'll note it reads sqlite3 (1.3.8-x86-mingw32). Change that to sqlite3 (1.3.8-x64-mingw32) and then run the bundle install command and everything should work like normal.
from Sqlite3 gem not loading, gem installed and specified in project

Answer 2

I had this on OSX for a spec/dummy app. Without rebuilding the gemset (just rebuilding sqlite3), it was unsuccessful.
I had to do the following to get everything built properly:
rvm gemset empty
brew update
brew install sqlite
bundle update