http://blog.zhangyu.so/ta/2015/06/03/stop-robotframework-in-a-monitor-thread/

monitor_lib.py

# lib.py
import signal
from robot.running import EXECUTION_CONTEXTS
from robot.running.keywords import Keyword
import thread
import os

def do_error_log_monitoring():
    def _stop_execution(signum, frame):
        Keyword('fatal error', ()).run(EXECUTION_CONTEXTS.current)
    def _monitor_log():
        import time
        time.sleep(5)
        os.kill(os.getpid(), signal.SIGUSR1)
    signal.signal(signal.SIGUSR1, _stop_execution)
    thread.start_new_thread(_monitor_log, ())