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/5240#issuecomment-830688362,https://api.github.com/repos/pydata/xarray/issues/5240,830688362,MDEyOklzc3VlQ29tbWVudDgzMDY4ODM2Mg==,14808389,2021-05-01T20:15:56Z,2021-05-02T11:46:19Z,MEMBER,"The `repr` will be fixed by #5149, but we should probably still fix that. Since `dim` is the dimension to concatenate along I guess we should fall back to that (not sure though). Thoughts, @pydata/xarray?

For reference, the conversion happens in `_calc_concat_dim_coord` (""`else`""): https://github.com/pydata/xarray/blob/04acabb50bea9f48224464850ae5a918e57406e5/xarray/core/concat.py#L244-L265

","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,873713013
https://github.com/pydata/xarray/issues/5240#issuecomment-830666545,https://api.github.com/repos/pydata/xarray/issues/5240,830666545,MDEyOklzc3VlQ29tbWVudDgzMDY2NjU0NQ==,14808389,2021-05-01T17:32:57Z,2021-05-01T17:33:04Z,MEMBER,"> would've expected the name of the new coordinate to be the name of the DataArray variable

that's exactly what it's doing: it uses the name of `DataArray([0, 1], dims='b')`, which is `None`. To fix that, you can assign a name to the `DataArray`:
```python
In [3]: a = xr.DataArray([0], dims='a')
   ...: out = xr.concat([a, a], dim=xr.DataArray([0, 1], dims='b', name=""x""))
   ...: out
Out[3]: 
<xarray.DataArray (b: 2, a: 1)>
array([[0],
       [0]])
Coordinates:
    x        (b) int64 0 1
Dimensions without coordinates: b, a
```

Since `None` is not a particularly good name, we could raise for unnamed `DataArray` objects (not sure if falling back to `dims` for 1D `DataArray` objects would be a good idea)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,873713013