Fix zerodim test

Author: dcherian

xarray/core/indexing.py

@@ -18,7 +18,13 @@
 from .npcompat import DTypeLike
 from .nputils import NumpyVIndexAdapter
 from .options import OPTIONS
-from .pycompat import dask_version, integer_types, is_duck_dask_array, sparse_array_type
+from .pycompat import (
+    dask_version,
+    integer_types,
+    is_duck_array,
+    is_duck_dask_array,
+    sparse_array_type,
+)
 from .types import T_Xarray
 from .utils import (
     NDArrayMixin,
@@ -532,9 +538,11 @@ def get_duck_array(self):
         array = as_indexable(self.array)
         array = array[self.key]
         if isinstance(array, ExplicitlyIndexed):
-            return array.get_duck_array()
-        else:
-            return array
+            array = array.get_duck_array()
+        if not is_duck_array(array):
+            # This hack is necessary for 0D netCDF4 variables
+            array = np.asarray(array)
+        return array
 
     def transpose(self, order):
         return LazilyVectorizedIndexedArray(self.array, self.key).transpose(order)