issue_comments: 1128588208

This data as json

html_url issue_url id node_id user created_at updated_at author_association body reactions performed_via_github_app issue
https://github.com/pydata/xarray/issues/6610#issuecomment-1128588208 https://api.github.com/repos/pydata/xarray/issues/6610 1128588208 IC_kwDOAMm_X85DROOw 22245117 2022-05-17T08:40:04Z 2022-05-17T15:04:04Z CONTRIBUTOR

I'm getting errors with multi-indexes and flox. Is this expected and related to this issue, or should I open a separate issue?

```python import numpy as np

import xarray as xr

ds = xr.Dataset( dict(a=(("z",), np.ones(10))), coords=dict(b=(("z"), np.arange(2).repeat(5)), c=(("z"), np.arange(5).repeat(2))), ).set_index(bc=["b", "c"]) grouped = ds.groupby("bc")

with xr.set_options(use_flox=False): grouped.sum() # OK

with xr.set_options(use_flox=True): grouped.sum() # Error Traceback (most recent call last): File "/Users/mattia/MyGit/test.py", line 15, in <module> grouped.sum() File "/Users/mattia/MyGit/xarray/xarray/core/_reductions.py", line 2763, in sum return self._flox_reduce( File "/Users/mattia/MyGit/xarray/xarray/core/groupby.py", line 661, in _flox_reduce result = xarray_reduce( File "/Users/mattia/mambaforge/envs/sarsen_dev/lib/python3.10/site-packages/flox/xarray.py", line 373, in xarray_reduce actual[k] = v.expand_dims(missing_group_dims) File "/Users/mattia/MyGit/xarray/xarray/core/dataset.py", line 1427, in setitem self.update({key: value}) File "/Users/mattia/MyGit/xarray/xarray/core/dataset.py", line 4432, in update merge_result = dataset_update_method(self, other) File "/Users/mattia/MyGit/xarray/xarray/core/merge.py", line 1070, in dataset_update_method return merge_core( File "/Users/mattia/MyGit/xarray/xarray/core/merge.py", line 722, in merge_core aligned = deep_align( File "/Users/mattia/MyGit/xarray/xarray/core/alignment.py", line 824, in deep_align aligned = align( File "/Users/mattia/MyGit/xarray/xarray/core/alignment.py", line 761, in align aligner.align() File "/Users/mattia/MyGit/xarray/xarray/core/alignment.py", line 550, in align self.assert_unindexed_dim_sizes_equal() File "/Users/mattia/MyGit/xarray/xarray/core/alignment.py", line 450, in assert_unindexed_dim_sizes_equal raise ValueError( ValueError: cannot reindex or align along dimension 'bc' because of conflicting dimension sizes: {10, 6} (note: an index is found along that dimension with size=10) ```

 
{
    "total_count": 0,
    "+1": 0,
    "-1": 0,
    "laugh": 0,
    "hooray": 0,
    "confused": 0,
    "heart": 0,
    "rocket": 0,
    "eyes": 0
}
   1236174701