Right way to make process calls and use Timeout.timeout (example).

run_with_timeout.rb

def run_with_timeout(cmd, limit)
  Open3.popen3(cmd) do |_, stdout, stderr, wait_thr|
    output, pid = [], wait_thr.pid
    begin
      Timeout.timeout(limit) do
        output = [stdout.read, stderr.read]
        Process.wait(pid)
      end
    rescue Errno::ECHILD
    rescue Timeout::Error
      Process.kill('HUP', pid)
      fail
    end
    output
  end
end

run_with_timeout('sleep 5; echo 1', 10)   # ["1\n", ""]
run_with_timeout('sleep 11; echo 2', 10)  # throws Timeout::Error