Recipe package system.

recipe_engine/config_types.py

Index: recipe_engine/config_types.py
diff --git a/recipe_engine/config_types.py b/recipe_engine/config_types.py
index 5dd216e1fcaed3a0494c83efb62110c980415e84..c0cb52f280c95f8ef9954b85d26847e8ecbbd26e 100644
--- a/recipe_engine/config_types.py
+++ b/recipe_engine/config_types.py
@@ -7,8 +7,7 @@ import re
 
 from collections import namedtuple
 
-from infra.libs import infra_types
-
+from . import types
 
 RECIPE_MODULE_PREFIX = 'RECIPE_MODULES'
 
@@ -20,9 +19,8 @@ def ResetTostringFns():
 def json_fixup(obj):
   if isinstance(obj, RecipeConfigType):
     return str(obj)
-  thawed = infra_types.thaw(obj)
-  if thawed is not obj:  # i.e. it was a frozen type
-    return thawed
+  if isinstance(obj, types.FrozenDict):
+    return dict(obj)
   raise TypeError("%r is not JSON serializable" % obj)