Prevent creating auth files when there is no suite service directory

cylc/flow/scheduler_cli.py

@@ -232,13 +232,18 @@ def scheduler_cli(parser, options, args, is_restart=False):
     except SuiteServiceFileError as exc:
         sys.exit(exc)
 
+    suite_srv_dir = SuiteSrvFilesManager().get_suite_srv_dir(reg)
+
+    if not os.path.exists(suite_srv_dir):
+        sys.stderr.write(f'suite service directory not found '
+                         f'at: {suite_srv_dir}\n')
+        sys.exit(1)
+
     # Create auth files if needed.
     SuiteSrvFilesManager().create_auth_files(reg)
 
     # Extract job.sh from library, for use in job scripts.
-    extract_resources(
-        SuiteSrvFilesManager().get_suite_srv_dir(reg),
-        ['etc/job.sh'])
+    extract_resources(suite_srv_dir, ['etc/job.sh'])
 
     # Check whether a run host is explicitly specified, else select one.
     if not options.host: