list all not running on-watch service

slapos/grid/SlapObject.py

@@ -893,16 +893,19 @@ class Partition(object):
 
     print(service_list)
 
-    has_failed_on_watch_process = False
+    bad_service_list = []
     with self.getSupervisorRPC() as supervisor:
       all_process = supervisor.getAllProcessInfo()
       print(all_process)
       for process in all_process:
         if 'on-watch' in process['name'] and process['statename'] != "RUNNING":
           self.logger.info('On watch service %r is not running' % process['name'])
-          has_failed_on_watch_process = True
-    if has_failed_on_watch_process:
-      raise ChildProcessError("Some on-watch process is not running, please check the log.")
+          bad_service_list.append(process['name'])
+    if len(bad_service_list) > 0:      
+      raise ChildProcessError(
+        "The following on-watch service(es) is not running, \
+        for the details, please check the corresponding log: %s",
+        '\n'.join(bad_service_list))
     
   def cleanupFolder(self, folder_path):
     """Delete all files and folders in a specified directory