As noted in the SproutCore documentation you need to have RubyGems 1.3.0 installed. You also need a full Ruby distribution (including openssl bits), which is not so clearly noted. Here’s the steps I followed on my Ubuntu 8.10 system.
Step 1. Update to the latest version of RubyGems
Type the following to update RubyGems:
sudo gem update --system
Note: thats a double dash before system.
On my system this created a new executable /usr/bin/gem1.8 rather than overwriting the existing /usr/bin/gem. You need to replace the old file with the new file manually otherwise you’ll get:
/usr/bin/gem:23: uninitialized constant Gem::GemRunner (NameError)
sudo rm /usr/bin/gem sudo ln -s /usr/bin/gem1.8 /usr/bin/gem
Step 2. Install full Ruby Distribution
Seems that out of the box Ubuntu 8.10 lacks a full ruby distribution, the following will ensure all components of ruby are installed (In particular SproutCore, via Mongrel depends on the libopenssl-ruby1.8 package).
sudo apt-get install ruby1.8 ruby1.8-dev ri1.8 rdoc1.8 irb1.8 ruby1.8-elisp ruby1.8-examples libdbm-ruby1.8 libgdbm-ruby1.8 libtcltk-ruby1.8 libopenssl-ruby1.8 libreadline-ruby1.8
Step 3. Install SproutCore
With the above steps completed you are now ready to install SproutCore per the official documentation.