3.0.0b2 rails generator - no such file: singleton_class

> rails --help

or

> rails whatever

  _GEMS_/gems/railties-3.0.0.beta2/lib/rails/generators.rb:6:in `require': no such file to load -- active_support/core_ext/object/singleton_class (LoadError)
from _GEMS_/gems/railties-3.0.0.beta2/lib/rails/generators.rb:6:in `<top (required)>'
from _GEMS_/gems/railties-3.0.0.beta2/lib/rails/commands/application.rb:10:in `require'
from _GEMS_/gems/railties-3.0.0.beta2/lib/rails/commands/application.rb:10:in `<top (required)>'
from _GEMS_/gems/railties-3.0.0.beta2/bin/rails:30:in `require'
from _GEMS_/gems/railties-3.0.0.beta2/bin/rails:30:in `<top (required)>'
from _GEMS_/bin/rails:19:in `load'
from _GEMS_/bin/rails:19:in `<main>'

I noticed by looking at activesupport 3.0.0b2 that singleton_class has been removed, so commenting the require (line 6) in http://github.com/rails/rails/blob/v3.0.0.beta2/railties/lib/rails/... will resolve the issue, but I haven't checked if somewhere something's using the removed class.

See you