REVERT TO CONSOLE

This is not a complete step-by-step set of instructions, but it should be pretty close.

sudo apt-get install ruby-full build-essential

wget http://rubyforge.org/frs/download.php/69365/rubygems-1.3.6.tgz
 tar -zxvf rubygems-1.3.6.tgz
 cd rubygems-1.3.6/
 sudo ruby setup.rb
 sudo ln -s /usr/bin/gem1.8 /usr/bin/gem
 sudo gem update --system
sudo gem install rake

sudo apt-get install zlib1g-dev uuid-dev

sudo gem install ncursesw

 # We need this extra package
 sudo apt-get install libncurses5-dev libncursesw5-dev
 sudo gem install sup
 sup

Also had to make one code change, described here

#optional
#installed offlineimap
sudo apt-get install offlineimap

Links
Sup RubyForge Wiki
Use offlineimap with gmail – add some hooks
Setting up offlineimap for gmail backup
handy script examples to add sources