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/3315#issuecomment-535052060,https://api.github.com/repos/pydata/xarray/issues/3315,535052060,MDEyOklzc3VlQ29tbWVudDUzNTA1MjA2MA==,2448579,2019-09-25T14:32:48Z,2019-09-25T14:32:48Z,MEMBER,`concat` ignores `DataArray.name`. I don't know if we should consider it a bug or a feature :),"{""total_count"": 1, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 1}",,494906646
https://github.com/pydata/xarray/issues/3315#issuecomment-532780805,https://api.github.com/repos/pydata/xarray/issues/3315,532780805,MDEyOklzc3VlQ29tbWVudDUzMjc4MDgwNQ==,2448579,2019-09-18T17:16:36Z,2019-09-18T17:16:36Z,MEMBER,"Yes/

https://github.com/pydata/xarray/blob/fddced063b7ecbea6254dc1008bb4db15a5d9304/xarray/tests/test_combine.py#L467-L478","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,494906646
https://github.com/pydata/xarray/issues/3315#issuecomment-532777471,https://api.github.com/repos/pydata/xarray/issues/3315,532777471,MDEyOklzc3VlQ29tbWVudDUzMjc3NzQ3MQ==,2448579,2019-09-18T17:07:39Z,2019-09-18T17:07:39Z,MEMBER,"This honestly makes no sense to me.
```
da1 = xr.DataArray(name=""a"", data=[[0]], dims=[""x"", ""y""])
da2 = xr.DataArray(name=""b"", data=[[1]], dims=[""x"", ""y""])
da3 = xr.DataArray(name=""a"", data=[[2]], dims=[""x"", ""y""])
da4 = xr.DataArray(name=""b"", data=[[3]], dims=[""x"", ""y""])
xr.combine_nested([[da1, da2], [da3, da4]], concat_dim=[""x"", ""y""])
```

These are dataarrays with two different names. Why is this the expected result?
```
<xarray.DataArray 'a' (x: 2, y: 2)>
array([[0, 1],
       [2, 3]])
Dimensions without coordinates: x, y
```

 That error arises because it's trying to concatenate data_vars `a` and `b` but there are datasets that don't have `a`. If you set those DataArrays to have the same name, this will work.

```
da1 = xr.DataArray(name=""a"", data=[[0]], dims=[""x"", ""y""])
da2 = xr.DataArray(name=""a"", data=[[1]], dims=[""x"", ""y""])
da3 = xr.DataArray(name=""a"", data=[[2]], dims=[""x"", ""y""])
da4 = xr.DataArray(name=""a"", data=[[3]], dims=[""x"", ""y""])

ds1 = da1.to_dataset()
ds2 = da2.to_dataset()
ds3 = da3.to_dataset()
ds4 = da4.to_dataset()
xr.combine_nested([[ds1, ds2], [ds3, ds4]], concat_dim=[""x"", ""y""])
```

```
<xarray.Dataset>
Dimensions:  (x: 2, y: 2)
Dimensions without coordinates: x, y
Data variables:
    a        (x, y) int64 0 1 2 3
```

ping @TomNicholas ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,494906646