write to tmp file and move for yaml changes to ensure a good state in…

… case of multiple processes

src/util/config.py

@@ -2,6 +2,8 @@
 import pkg_resources
 import sys
 import yaml
+import shutil
+import os
 
 from pathlib import Path
 from typing import Dict, Any, Callable, Optional, Union
@@ -33,8 +35,9 @@ def config_path_for_filename(root_path: Path, filename: Union[str, Path]) -> Pat
 
 def save_config(root_path: Path, filename: Union[str, Path], config_data: Any):
     path = config_path_for_filename(root_path, filename)
-    with open(path, "w") as f:
+    with open(path.with_suffix('.' + str(os.getpid())), "w") as f:
         yaml.safe_dump(config_data, f)
+    shutil.move(path.with_suffix('.' + str(os.getpid())), path)
 
 
 def load_config(