fix(clp-package): Ensure at least one worker in default calculations (fixes #1509). (#1547)

Author: junhaoliao

components/clp-package-utils/clp_package_utils/controller.py

@@ -819,7 +819,7 @@ def _get_num_workers() -> int:
         :return: Number of worker processes to run.
         """
         # This will change when we move from single to multi-container workers. See y-scope/clp#1424
-        return multiprocessing.cpu_count() // 2
+        return max(1, multiprocessing.cpu_count() // 2)
 
     def _get_docker_file_name(self) -> str:
         """