Rails 2.3.11 fails with newer Rubygems (~1.8.1)

http://rubyforge.org/tracker/index.php?func=detail&aid=29188&am...

rails-2.3.11/lib/rails/gem_dependency.rb:277:in `==': undefined
method `name' for "POpen4":String (NoMethodError)
from lib/rubygems/dependency.rb:217:in `==='
from lib/rubygems/dependency.rb:217:in `matching_specs'
from lib/rubygems/specification.rb:539:in `find_all'
from lib/rubygems/specification.rb:403:in `each'
from lib/rubygems/specification.rb:402:in `each'
from lib/rubygems/dependency.rb:216:in `find_all'
from lib/rubygems/dependency.rb:216:in `matching_specs'
from lib/rubygems/dependency.rb:238:in `to_specs'
from lib/rubygems/dependency.rb:256:in `to_spec'
from lib/rubygems.rb:1182:in `gem'
from rails-2.3.11/lib/rails/gem_dependency.rb:75:in `add_load_paths'
from rails-2.3.11/lib/initializer.rb:301:in `add_gem_load_paths'
from rails-2.3.11/lib/initializer.rb:301:in `each'
from rails-2.3.11/lib/initializer.rb:301:in `add_gem_load_paths'
from rails-2.3.11/lib/initializer.rb:132:in `process'
from rails-2.3.11/lib/initializer.rb:113:in `send'
from rails-2.3.11/lib/initializer.rb:113:in `run'

There are also a number of deprecations which spam the console, which I'm sure you'll see when this is fixed and tested.