class Gem::Ext::RakeBuilder

def self.build(extension, directory, dest_path, results, args=[], lib_dir=nil)
  if File.basename(extension) =~ /mkrf_conf/i then
    cmd = "#{Gem.ruby} #{File.basename extension}"
    cmd << " #{args.join " "}" unless args.empty?
    run cmd, results
  end
  # Deal with possible spaces in the path, e.g. C:/Program Files
  dest_path = '"' + dest_path.to_s + '"' if dest_path.to_s.include?(' ')
  rake = ENV['rake']
  rake ||= begin
             "#{Gem.ruby} -rubygems #{Gem.bin_path('rake', 'rake')}"
           rescue Gem::Exception
           end
  rake ||= Gem.default_exec_format % 'rake'
  cmd = "#{rake} RUBYARCHDIR=#{dest_path} RUBYLIBDIR=#{dest_path}" # ENV is frozen
  run cmd, results
  results
end