nonexistent mysql adapter during bundle exec rake asset:precompile

Question

I'm trying to precompile my assets on the production server using bundle exec rake asset:precompile. When is run the rake, I get the error below. What is causing this?

[x]$ bundle exec rake asset:precompile
/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby /home/admin/ento/vendor/bundle/ruby/1.9.1/bin/rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets
rake aborted!
database configuration specifies nonexistent mysql adapter
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_specification.rb:133:in `establish_connection'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.11/lib/active_record/railtie.rb:82:in `block (2 levels) in <class:Railtie>'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/lazy_load_hooks.rb:25:in `each'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.11/lib/active_record/railtie.rb:74:in `block in <class:Railtie>'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `instance_exec'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `run'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:55:in `block in run_initializers'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `each'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `run_initializers'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/application.rb:136:in `initialize!'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/railtie/configurable.rb:30:in `method_missing'
/home/admin/ento/config/environment.rb:5:in `<top (required)>'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:251:in `require'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:251:in `block in require'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:236:in `load_dependency'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:251:in `require'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/application.rb:103:in `require_environment!'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/railties-3.2.11/lib/rails/application.rb:297:in `block (2 levels) in initialize_tasks'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:93:in `block (2 levels) in <top (required)>'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:60:in `block (3 levels) in <top (required)>'
Tasks: TOP => environment
(See full trace by running task with --trace)
rake aborted!
Command failed with status (1): [/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/...]
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:12:in `ruby_rake_task'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:21:in `invoke_or_reboot_rake_task'
/home/admin/ento/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.11/lib/sprockets/assets.rake:29:in `block (2 levels) in <top (required)>'
Tasks: TOP => assets:precompile
(See full trace by running task with --trace)

Gemfile:

source 'https://rubygems.org'

gem 'rails', '3.2.11'

group :development do
    gem 'sqlite3'
end

group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1'

  gem 'uglifier', '>= 1.0.3'
  gem 'mysql'
end

gem 'jquery-rails'

group :production do
    gem 'mysql'
    gem 'activerecord-mysql-adapter'
end

gem 'devise'
gem 'paper_trail'
gem 'ckeditor_rails'
gem 'bootstrap-sass'
gem 'bootstrap-datepicker-rails'
gem 'carrierwave'
gem 'ransack'
gem 'nested_form'
gem 'mysql'
gem 'will_paginate'
gem 'capistrano'
gem 'therubyracer'
gem 'best_in_place'

database.yml

production:
  adapter: mysql
  host: localhost
  database: xxxx
  username: xxxx
  password: xxxx
  timeout: 5000

Answer 1

Not sure this is the solution, but for more recent Rails apps, you probably want to use the mysql2 gem. It looks like you're still on the old gem.