installing ruby on EC2 Amazon Unix, using capistrano

I'm trying to install ruby 1.9.3-p545 using capistrano again. What worked for me a year ago, seems to be broken by rvm:

require "rvm/capistrano"

set :rvm_ruby_string, 'ruby-1.9.3-p327'
set :rvm_type, :user
set :rvm_install_ruby_params, '--with-opensll-dir=$HOME/.rvm/usr'

def rvm_bin
    '$HOME/.rvm/bin/rvm'
end

namespace :deploy do
    task :step do
        rvm.install_rvm
        run "#{rvm_bin} autolibs enable"
        rvm.install_ruby
        run "#{rvm_bin} alias create default #{rvm_ruby_string}"
        run 'echo "source ~/.rvm/environments/default" >> $HOME/.bashrc'
        run 'which ruby && ruby -v'
        run 'gem install --no-ri --no-rdoc rake rack net-ssh bundler'
    end
end

It looks like the rvm autolibs enable doesn't work anymore, because I get the following error message:

Checking requirements for amazon.
Missing required packages: libyaml-devel libffi-devel readline-devel openssl-devel bison
RVM autolibs is now configured with mode '2' => 'check and stop if missing',
please run `rvm autolibs enable` to let RVM do its job or run and read `rvm autolibs [help]`

I think there must be others out there, using capistrano to install ruby. I've tried to install ruby from sources, but then I ran into problems with missing yaml support.

Any thoughts, any pointers?

Solution

So, this is my solution without rmv. Please let me know, if you have any improvements, thoughts or critics:

namespace :deploy do
    RUBY_VERSION = 'ruby-1.9.3-p545'

    task :step do
        # remove default ruby and install dependencies     
        run "#{sudo} yum erase --assumeyes ruby"
        run "#{sudo} yum install --assumeyes readline-devel openssl-devel libyaml-devel"
        # Add the installed ruby to PATH
        run "echo 'export PATH=$PATH:$HOME/bin' >> $HOME/.bashrc"
        run "source $HOME/.bashrc"
        # Build and install
        run "wget http://cache.ruby-lang.org/pub/ruby/1.9/#{RUBY_VERSION}.tar.gz"
        run "tar zxvf #{RUBY_VERSION}.tar.gz"
        run "cd #{RUBY_VERSION} && ./configure --disable-install-doc --enable-shared --prefix=$HOME && make && make install"
        # Check installation and install very basic gems
        run 'which ruby && ruby -v'
        run "gem install --no-ri --no-rdoc rake rack net-ssh bundler"
    end
end