follow the change in signature of xarray.Index.equals (#324)

* adapt to the newer API of equals

* add pooch and netcdf4 to the dev env

* trigger the future warning

* changelog

* comment on the passing of exclude

(since that will break for indexes that don't support `exclude`)

Author: keewis

docs/whats-new.rst

@@ -20,6 +20,8 @@ What's new
   By `Justus Magin <https://github.com/keewis>`_.
 - Added the :py:func:`pint_xarray.expects` decorator to allow wrapping quantity-unaware functions (:issue:`141`, :pull:`316`).
   By `Justus Magin <https://github.com/keewis>`_ and `Tom Nicholas <https://github.com/TomNicholas>`_.
+- Follow the change in signature of :py:meth:`xarray.Index.equals` (:issue:`322`, :pull:`324`)
+  By `Justus Magin <https://github.com/keewis>`_.
 
 0.5.1 (10 Aug 2025)
 -------------------

pint_xarray/index.py

@@ -71,16 +71,18 @@ def join(self, other, how="inner"):
     def reindex_like(self, other):
         raise NotImplementedError()
 
-    def equals(self, other):
+    def equals(self, other, *, exclude=None):
         if not isinstance(other, PintIndex):
             return False
 
         # for now we require exactly matching units to avoid the potentially expensive conversion
         if self.units != other.units:
             return False
 
-        # last to avoid the potentially expensive comparison
-        return self.index.equals(other.index)
+        # Explicitly pass `exclude`, the index does not officially support
+        # indexes other than the PandasIndex
+        # Last to avoid the potentially expensive comparison
+        return self.index.equals(other.index, exclude=exclude)
 
     def roll(self, shifts):
         return self._replace(self.index.roll(shifts))

pint_xarray/tests/test_index.py

@@ -205,6 +205,28 @@ def test_equals(other, expected):
     assert actual == expected
 
 
+@pytest.mark.filterwarnings("error")
+def test_align_equals_warning():
+    index1 = PintIndex(
+        index=PandasIndex(pd.Index([1, 2]), dim="x"),
+        units={"x": ureg.Unit("m")},
+    )
+    index2 = PintIndex(
+        index=PandasIndex(pd.Index([0, 1, 2]), dim="y"),
+        units={"y": ureg.Unit("m")},
+    )
+
+    ds = xr.Dataset(
+        {"a": (["y", "x"], [[-1, 1], [0, 2], [1, 3]])},
+        coords=xr.Coordinates(
+            {"x": [1, 2], "y": [0, 1, 2]}, indexes={"x": index1, "y": index2}
+        ),
+    )
+
+    # trigger comparison
+    ds["a"] * ds["x"] * ds["y"]
+
+
 @pytest.mark.parametrize(
     ["shifts", "expected_index"],
     (