class Gem::Ext::Builder

def self.make(dest_path, results)
  unless File.exist? 'Makefile' then
    raise Gem::InstallError, "Makefile not found:\n\n#{results.join "\n"}"
  end
  mf = Gem.read_binary 'Makefile'
  mf = mf.gsub(/^RUBYARCHDIR\s*=\s*\$[^$]*/, "RUBYARCHDIR = #{dest_path}")
  mf = mf.gsub(/^RUBYLIBDIR\s*=\s*\$[^$]*/, "RUBYLIBDIR = #{dest_path}")
  File.open('Makefile', 'wb') {|f| f.print mf}
  # try to find make program from Ruby configure arguments first
  RbConfig::CONFIG['configure_args'] =~ /with-make-prog\=(\w+)/
  make_program = $1 || ENV['MAKE'] || ENV['make']
  unless make_program then
    make_program = (/mswin/ =~ RUBY_PLATFORM) ? 'nmake' : 'make'
  end
  ['', ' install'].each do |target|
    cmd = "#{make_program}#{target}"
    run(cmd, results, "make#{target}")
  end
end