simplification

api/py/ai/chronon/repo/run.py

@@ -491,13 +491,13 @@ def run(self):
                         additional_args=os.environ.get("CHRONON_CONFIG_ADDITIONAL_ARGS", ""),
                     )
                     command_list.append(command)
-        first_command = command_list.pop(0)
-        check_call(first_command)
-        if len(command_list) > 0:
+        if len(command_list) > 1:
             # parallel backfill mode
             with multiprocessing.Pool(processes=int(self.parallelism)) as pool:
                 logging.info("Running args list {} with pool size {}".format(command_list, self.parallelism))
                 pool.map(check_call, command_list)
+        elif len(command_list) == 1:
+            check_call(command_list[0])
 
     def _gen_final_args(self, start_ds=None, end_ds=None):
         base_args = MODE_ARGS[self.mode].format(