return error from subprocess run

# ********************************************************************************************

#

import os

import subprocess

import sys

import threading

import time

import math

import numpy as np

from operator import itemgetter

from itertools import groupby

# sys.path.insert(0,"/opt/mantidnightly/bin")

# sys.path.insert(0,"/opt/mantidnightly/lib")

from mantid.simpleapi import *

from mantid.kernel import *

from mantid.geometry import PointGroupFactory, SpaceGroupFactory, UnitCell, Goniometer

from mantid import config

config['Q.convention'] = "Crystallography"

DownloadInstrument(ForceUpdate=True)

from spectrum2 import *

from absor_sphere import *

print("API Version")

print(apiVersion())

# how the the list of runs will be processed in parallel. 

print("\n*********************************************************************************")

print("************** Start Peak Integration *******************************************")

#

# ProcessThread is a simple local class.  Each instance of ProcessThread is 

# a thread that starts a command line process to reduce one run.

#

class ProcessThread(threading.Thread):

   command = ""

    def __init__(self):

        super().__init__()

        self.return_code = None

    def setCommand(self, command=""):

        self.command = command

    def run(self):

      print(('STARTING PROCESS: ' + self.command))

      os.system( self.command )

        print('STARTING PROCESS:', self.command)

        self.return_code = subprocess.run(self.command, shell=True)

# -------------------------------------------------------------------------

#

index = 0

for r_num in run_nums:

    list.append(ProcessThread())

  cmd = 'mantidpython -u ' + reduce_one_run_script + ' ' + config_file_name + ' ' + str(r_num)

    cmd = 'python -u ' + reduce_one_run_script + ' ' + config_file_name + ' ' + str(r_num)

    if slurm_queue_name is not None:

        console_file = output_directory + "/" + str(r_num) + "_output.txt"

        cmd = 'srun -p ' + slurm_queue_name + \

#

all_done = False

active_list = []

return_codes = []

while not all_done:

    if (len(list) > 0 and len(active_list) < max_processes):

        thread = list[0]

    for thread in active_list:

        if not thread.is_alive():

            active_list.remove(thread)

            return_codes.append(thread.return_code)

    if len(list) == 0 and len(active_list) == 0:

        all_done = True

print("**************************************************************************************\n")

print('Config file: ' + config_file_name)

for code in return_codes:

    if code != 0:

        print('Finished with errors')

        sys.exit(1)