def build
      logger.debug "Building '#{target}'"
      File.unlink(target) if File.exist?(target)
      build_commands.each do |command|
        stdout, stderr = shell(command)
        raise BuildFailure.new("Error: command '#{command}' failed: #{stderr} #{stdout}") if not $?.success?
      end
      raise BuildFailure.new("'#{target}' not created") if not File.exist?(target)
    end
def build
      logger.debug "Building '#{target}'"
      File.unlink(target) if File.exist?(target)
      build_commands.each do |command|
        stdout, stderr = shell(command)
        raise BuildFailure.new("Error: command '#{command}' failed: #{stderr} #{stdout}") if not $?.success?
      end
      raise BuildFailure.new("'#{target}' not created") if not File.exist?(target)
    end
main actions