Ubuntu Server v12.10 64bit , Ruby 2.1.1 (rbenv), Rails 4.0.3

ubuntu_rbenv_rails

#
# See: Setup Ruby On Rails onUbuntu 13.10 http://gorails.com/setup/ubuntu/13.10
#

# package
sudo apt-get update
sudo apt-get -y install git
sudo apt-get -y install curl g++ make
sudo apt-get -y install zlib1g-dev libssl-dev libreadline-dev libyaml-dev libxml2-dev libxslt-dev
sudo apt-get -y install sqlite3 libsqlite3-dev
# PostgreSQL
# sudo apt-get install libpq-dev

# rbenv
cd
git clone git://github.com/sstephenson/rbenv.git .rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
exec $SHELL

# ruby-build
mkdir -p ~/.rbenv/plugins
cd ~/.rbenv/plugins
git clone git://github.com/sstephenson/ruby-build.git

# ruby
rbenv install 2.1.1
rbenv rehash
rbenv global 2.1.1
rbenv version

# .gemrc
echo "install: --no-ri --no-rdoc" > ~/.gemrc
echo "update: --no-ri --no-rdoc" >> ~/.gemrc

# rails
gem install rails --version="~> 4.0.3"
rbenv rehash

# verification
cd
mkdir work
cd work
rails new foo --skip-bundle
cd foo
vi Gemfile
  gem 'therubyracer', :platforms => :ruby
bundle install
rails g scaffold user name:string email:string
rake db:migrate
rails s