id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
232350436,MDU6SXNzdWUyMzIzNTA0MzY=,1434,xr.concat loses coordinate dtype information with recarrays in 0.9,2805515,closed,0,,,10,2017-05-30T19:04:07Z,2023-01-23T16:22:15Z,2023-01-23T10:23:48Z,CONTRIBUTOR,,,,"Simple example script:

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

p1 = np.array([('A', 180), ('B', 150), ('C', 200)], dtype=[('name', '|S256'), ('height', int)])
p2 = np.array([('D', 170), ('E', 250), ('F', 150)], dtype=[('name', '|S256'), ('height', int)])

data1 = np.arange(50, 80, 1, dtype=np.float)
data2 = data1 * 2

dims = ['measurement', 'participant']

da1 = xr.DataArray(
    data1.reshape(10, 3),
    coords={
        'measurement': np.arange(10),
        'participant': p1,
        'samplerate': 1
    },
    dims=dims
)

da2 = xr.DataArray(
    data2.reshape(10, 3),
    coords={
        'measurement': np.arange(10),
        'participant': p2,
        'samplerate': 1
    },
    dims=dims
)

combined = xr.concat([da1, da2], dim='participant')
print(da1.participant.dtype)
print(da2.participant.dtype)
print(combined.participant.dtype)
```

With `xarray` version 0.9.5 (and 0.8.2), this results in:

```
[('name', 'S256'), ('height', '<i8')]
[('name', 'S256'), ('height', '<i8')]
object
```

We have to go all the way back to xarray version 0.7 to get the expected behavior:

```
[('name', 'S256'), ('height', '<i8')]
[('name', 'S256'), ('height', '<i8')]
[('name', 'S256'), ('height', '<i8')]
```","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/1434/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue