build_extensions

# File lib/rubygems/ext/builder.rb, line 179
  def build_extensions
    return if @spec.extensions.empty?

    if @build_args.empty?
      say "Building native extensions.  This could take a while..."
    else
      say "Building native extensions with: '#{@build_args.join ' '}'"
      say "This could take a while..."
    end

    dest_path = @spec.extension_dir

    FileUtils.rm_f @spec.gem_build_complete_path

    @ran_rake = false # only run rake once

    @spec.extensions.each do |extension|
      break if @ran_rake

      build_extension extension, dest_path
    end

    FileUtils.touch @spec.gem_build_complete_path
  end