method to wrap a subprocess in a timeout

timed_subprocess.rb

require 'timeout'

SUBPROCESS_TIMEOUT = 90

def timed_shell_command(cmd)
  begin
    Timeout.timeout(SUBPROCESS_TIMEOUT) do
      subprocess = IO.popen(cmd)
      Process.wait subprocess.pid
      unless $?.success?
        raise "shell subprocess failed with exit status #{$?.exitstatus}: #{cmd}"
      end
    end
  rescue Timeout::Error
    Process.kill 9, subprocess.pid
    Process.wait subprocess.pid
    raise "shell subprocess timedout: #{cmd}"
  end
end