# File lib/headless/cli_util.rb, line 33
    def self.fork_process(command, pid_filename, log_filename='/dev/null')
      pid = fork do
        STDERR.reopen(log_filename)
        exec command
        exit! 127 # safeguard in case exec fails
      end

      File.open pid_filename, 'w' do |f|
        f.puts pid
      end
    end