Rails 3.1rc1 on ubuntu 11.04 by rvm (step by step)

better formatted version here:

http://kaxing.logdown.org/posts/50-rails-31rc1-on-ubuntu-1104-by-rvm

Pre-Requires:
apt-get install rubygems git-core curl

Following steps please use normal user

Install RVM
curl -s https://rvm.beginrescueend.com/install/rvm -o rvm-installer ; chmod +x rvm-installer ; ./rvm-installer --version latest

Set up RVM into your bash profile
echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >> ~/.bashprofile && source .bashprofile

Install necessary package into RVM
rvm package install zlib && rvm package install openssl

Install Ruby 1.9.2-head and use
rvm install 1.9.2-head
rvm use 1.9.2-head --default

Create gemset for Rails 3.1rc1 and use it as default gemset
rvm gemset create rails31rc1
rvm gemset use rails31rc1 --default

Update gem and gems
gem install --system
gem update

Install Rails 3.1rc1 without doc to avoid rdoc error
gem install rails -v ">=3.1.0rc" --no-ri --no-rdoc --with-openssl-dir=$HOME/.rvm/usr --with-zlib-dir=$rvm_path/usr

notice: if you trying to use sqlite3 please install "libsqlite3-dev" by apt-get