FFI::Platform.windows? is not defined in rubinius

gistfile1.txt

$ ruby -rlibusb -e ''
An exception occurred requiring command line files
    undefined method `windows?' on FFI::Platform (Module) (NoMethodError)

Backtrace:
                 Kernel(Module)#windows? (method_missing) at kernel/delta/kernel.rb:81
                      LIBUSB::Call.__module_init__ (Call) at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/gems/1.9/gems/libusb-0.2.2/lib/libusb/call.rb:24
                          LIBUSB.__module_init__ (LIBUSB) at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/gems/1.9/gems/libusb-0.2.2/lib/libusb/call.rb:21
                                        Object#__script__ at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/gems/1.9/gems/libusb-0.2.2/lib/libusb/call.rb:19
                             Rubinius::CodeLoader.require at kernel/common/codeloader.rb:212
            Kernel(Module)#gem_original_require (require) at kernel/common/kernel.rb:648
                                   Kernel(Module)#require at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/lib/rubygems/custom_require.rb:36
                          LIBUSB.__module_init__ (LIBUSB) at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/gems/1.9/gems/libusb-0.2.2/lib/libusb.rb:19
                                        Object#__script__ at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/gems/1.9/gems/libusb-0.2.2/lib/libusb.rb:16
                             Rubinius::CodeLoader.require at kernel/common/codeloader.rb:212
  Kernel(Rubinius::Loader)#gem_original_require (require) at kernel/common/kernel.rb:648
                         Kernel(Rubinius::Loader)#require at /home/renaud/.rbenv/versions/rbx-2.0.0-dev/lib/rubygems/custom_require.rb:60
                         { } in Rubinius::Loader#requires at kernel/loader.rb:568
                                               Array#each at kernel/bootstrap/array.rb:68
                                Rubinius::Loader#requires at kernel/loader.rb:568
                                    Rubinius::Loader#main at kernel/loader.rb:814