zarr3

Author: floriankrb

pyproject.toml

@@ -56,7 +56,11 @@ dependencies = [
   "pyyaml",
   "semantic-version",
   "tqdm",
-  "zarr<=2.17",
+  # anemoi-datasets supports zarr 2 and zarr 3, but we still use only zarr 2:
+  # - we don't want to create zarr 3 datasets yet, as they will no be readable by zarr 2
+  # - anemoi-patching needs zarr 2 for patching
+  # - anemoi-registry needs zarr 2
+  "zarr<3",
 ]
 
 optional-dependencies.all = [

src/anemoi/datasets/create/__init__.py

@@ -172,6 +172,13 @@ def __init__(self, path: str):
         """
         self.path = path
 
+        if Zarr2AndZarr3.version == "3" and not os.environ.get("ANEMOI_DATASETS_ALLOW_BUILDING_ZARR3_DATASETS"):
+            raise ValueError(
+                "zarr 3 is installed. anemoi-datasets supports zarr 3, but the datasets build with zarr 3 will "
+                "not be readable by zarr 2. It is likely that you do not want to create a dataset with zarr 3. "
+                "Please uninstall zarr 3 and install zarr 2."
+            )
+
         _, ext = os.path.splitext(self.path)
         if ext != ".zarr":
             raise ValueError(f"Unsupported extension={ext} for path={self.path}")