Use iris.FUTURE.save_split_attrs = True to remove iris warning

environment.yml

@@ -20,7 +20,7 @@ dependencies:
   - geopy
   - humanfriendly
   - importlib_metadata  # required for Python < 3.10
-  - iris >=3.6.1
+  - iris >=3.8.0
   - iris-esmf-regrid >=0.7.0
   - isodate
   - jinja2

esmvalcore/_provenance.py

@@ -53,7 +53,7 @@ def attribute_to_authors(entity, authors):
 
 
 def attribute_to_projects(entity, projects):
-    """Attribute entity to projecs."""
+    """Attribute entity to projects."""
     namespace = 'project'
     create_namespace(entity.bundle, namespace)
 
@@ -193,7 +193,7 @@ def initialize_provenance(self, activity):
         self._initialize_ancestors(activity)
 
     def _initialize_namespaces(self):
-        """Inialize the namespaces."""
+        """Initialize the namespaces."""
         for namespace in ('file', 'attribute', 'preprocessor', 'task'):
             create_namespace(self.provenance, namespace)
 

esmvalcore/preprocessor/_io.py

@@ -35,6 +35,8 @@
     'alternative_dataset',
 }
 
+iris.FUTURE.save_split_attrs = True
+
 
 def _get_attr_from_field_coord(ncfield, coord_name, attr):
     if coord_name is not None:

setup.py

@@ -58,7 +58,7 @@
         'scipy>=1.6',
         # See the following issue for info on the iris pin below:
         # https://github.com/ESMValGroup/ESMValTool/issues/3239#issuecomment-1613298587
-        'scitools-iris>=3.6.1',
+        'scitools-iris>=3.8.0',
         'shapely>=2.0.0',
         'stratify>=0.3',
         'yamale',

tests/integration/conftest.py

@@ -34,7 +34,8 @@ def create_test_file(filename, tracking_id=None):
     attributes = {}
     if tracking_id is not None:
         attributes['tracking_id'] = tracking_id
-    cube = iris.cube.Cube([], attributes=attributes)
+    cube = iris.cube.Cube([])
+    cube.attributes.globals = attributes
 
     iris.save(cube, filename)
 

tests/integration/recipe/test_recipe.py

@@ -97,7 +97,8 @@ def create_test_file(filename, tracking_id=None):
     attributes = {}
     if tracking_id is not None:
         attributes['tracking_id'] = tracking_id
-    cube = iris.cube.Cube([], attributes=attributes)
+    cube = iris.cube.Cube([])
+    cube.attributes.globals = attributes
 
     iris.save(cube, filename)