issue_comments: 811309154

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https://github.com/pydata/xarray/issues/4824#issuecomment-811309154 https://api.github.com/repos/pydata/xarray/issues/4824 811309154 MDEyOklzc3VlQ29tbWVudDgxMTMwOTE1NA== 10194086 2021-03-31T18:24:19Z 2021-03-31T18:24:19Z MEMBER

But then it also overrides when it should concatenate...

```python import numpy as np import xarray as xr

data = np.arange(5).reshape(1, 5) x = np.arange(5) x_name = "lat"

da0 = xr.DataArray(data, dims=("t", x_name), coords={"t": [1], x_name: x}).to_dataset(name="a") x = x + 5 da1 = xr.DataArray(data, dims=("t", x_name), coords={"t": [2], x_name: x}).to_dataset(name="a") ds = xr.combine_by_coords((da0, da1), join="override")

outpython <xarray.Dataset> Dimensions: (lat: 5, t: 2) Coordinates: * lat (lat) int64 0 1 2 3 4 * t (t) int64 1 2 Data variables: a (t, lat) int64 0 1 2 3 4 0 1 2 3 4 ```

Again if we set x_name = "y" the following is returned:

```python <xarray.Dataset> Dimensions: (t: 1, y: 10) Coordinates: * t (t) int64 1 * y (y) int64 0 1 2 3 4 5 6 7 8 9 Data variables: a (t, y) int64 0 1 2 3 4 0 1 2 3 4

```

 
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