Ensure inputs to stack operation are aligned

holoviews/operation/datashader.py

@@ -618,6 +618,11 @@ def _process(self, overlay, key=None):
             coords = {kd.name: rgb.dimension_values(kd, False)
                       for kd in rgb.kdims}
             imgs.append(tf.Image(self.uint8_to_uint32(rgb), coords=coords, dims=dims))
+        try:
+            imgs = xr.align(*imgs, join='exact')
+        except ValueError:
+            raise ValueError('RGB inputs to stack operation could not be aligned, '
+                             'ensure they share the same grid sampling.')
         stacked = tf.stack(*imgs, how=self.p.compositor)
         arr = shade.uint32_to_uint8(stacked.data)[::-1]
         data = (coords[dims[1]], coords[dims[0]], arr[:, :, 0],