Forum: Ruby-core rubygems LoadError for ruby 2.0.0dev

I attempted to build ruby from source last night and while it seems to
have been successful, (ruby -v works) it fails with a rubygems loaderror
if I try to execute a file.

This is what I did (on Ubuntu 12.04):
git clone https://github.com/ruby/ruby.git
./configure
make
make test (there were no errors)

ruby -v
=> ruby 2.0.0dev (2012-12-12 trunk 38332) [i686 - linux]

The error
=> <internal:gem_prelude>:1:in `require': cannot load such file --
rubygems.rb (LoadError)
        from <internal:gem_prelude>:1:in `<compiled>'

The file is just supposed to print Hello World.

Is there something else that needs to be done ?
Thanks