def do_rubygems_update(version)
args = []
args.push '--prefix', Gem.prefix unless Gem.prefix.nil?
args << '--no-rdoc' unless options[:generate_rdoc]
args << '--no-ri' unless options[:generate_ri]
args << '--no-format-executable' if options[:no_format_executable]
update_dir = File.join Gem.dir, 'gems', "rubygems-update-#{version}"
Dir.chdir update_dir do
say "Installing RubyGems #{version}"
setup_cmd = "#{Gem.ruby} setup.rb #{args.join ' '}"
old = ENV["RUBYOPT"]
ENV.delete("RUBYOPT")
system setup_cmd
ENV["RUBYOPT"] = old if old
end
end