issue_comments: 1233148389

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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/6969#issuecomment-1233148389 https://api.github.com/repos/pydata/xarray/issues/6969 1233148389 IC_kwDOAMm_X85JgFnl 4160723 2022-08-31T16:16:26Z 2022-08-31T16:16:26Z MEMBER

Thanks for the report @bboutanquoi.

The issue seems to be related to set_index(), which in your example does not convert back the old multi-index coordinates back to regular variables:

```python y = y.set_index(multi=['sub_id', 'last_j']) type(y.composite_id.variable)

IndexVariable (should be Variable)

```

I guess it's similar to #6946 which is related to reset_index. 

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