require 'rake' unless defined? Rake gem 'rake-compiler', '~> 0.7.1' require "rake/extensiontask" Rake::ExtensionTask.new('utf8') do |ext| ext.cross_compile = true ext.cross_platform = ['x86-mingw32', 'x86-mswin32-60'] ext.lib_dir = File.join 'lib', 'utf8' end