Fix unpickling of Configuration

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [1.5.4](https://github.com/sdss/sdsstools/compare/1.5.3...1.5.4) - 2023-12-10
+
+- Fix unpickling of `Configuration` instances. This only seems relevant when trying to pass a `Configuration` object to a `multiprocessing` callback.
+
+
 ## [1.5.3](https://github.com/sdss/sdsstools/compare/1.5.2...1.5.3) - 2023-12-08
 
 - Vendorise `pydl`'s `yanny` module which can be accessed as `sdsstools.yanny`.

src/sdsstools/configuration.py

@@ -223,15 +223,22 @@ def __init__(
 
     def __getitem__(self, __key: str) -> Any:
         if self.strict_mode:
-            return super().__getitem__(__key)
+            return dict.__getitem__(self, __key)
 
         return self.get(__key)
 
     def __setitem__(self, __key: str, __value: Any) -> None:
-        if isinstance(__value, dict) and self.propagate_type:
-            __value = self.__class__(__value, strict_mode=self.strict_mode)
+        # We use getattr to give default values to the non-default dict attributes.
+        # This only seems to matter when pickling/unpickling, and at the end of
+        # unpickling the values are set correctly anyway.
 
-        return super().__setitem__(__key, __value)
+        if isinstance(__value, dict) and getattr(self, "propagate_type", True):
+            __value = self.__class__(
+                __value,
+                strict_mode=getattr(self, "strict_mode", False),
+            )
+
+        return dict.__setitem__(self, __key, __value)
 
     def get(self, __key: str, default: Any = None, strict: bool | None = None) -> Any:
         if (strict is None and self.strict_mode is True) or strict is True:

test/test_configuration.py

@@ -9,6 +9,7 @@
 import copy
 import inspect
 import io
+import multiprocessing
 import os
 import unittest.mock
 
@@ -379,3 +380,14 @@ def test_configuration_assignment_dot():
     conf["cat1.key1"] = {"subkey2": 2}
     assert len(conf) == 2
     assert conf["cat1.key1"] == {"subkey2": 2}
+
+
+def _process(config):
+    assert config["cat1"]["key1"] == "another_value"
+
+
+def test_configuration_with_multiprocessing(config_file):
+    config = Configuration(config_file)
+    config.propagate_type = False
+    with multiprocessing.Pool(2) as pool:
+        pool.apply(_process, (config,))