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/3666#issuecomment-571691258,https://api.github.com/repos/pydata/xarray/issues/3666,571691258,MDEyOklzc3VlQ29tbWVudDU3MTY5MTI1OA==,2448579,2020-01-07T17:35:51Z,2020-01-07T17:36:03Z,MEMBER,"@tlogan specifying `use_cftime` as True or False in the `open_dataset` call might be useful.

This suggests that the `RecursionError` in @keewis example is a result of trying to concatenate datasets with mixed `DatetimeIndex`  & `CFTimeIndex` indexes.
```
In [18]: files = glob.glob(""*.nc"") 
    ...: datasets = [xr.open_dataset(file) for file in files] 
    ...: xr.concat(datasets, dim=""new_dim"")
RecursionError
```","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,546303413
https://github.com/pydata/xarray/issues/3666#issuecomment-571667543,https://api.github.com/repos/pydata/xarray/issues/3666,571667543,MDEyOklzc3VlQ29tbWVudDU3MTY2NzU0Mw==,14808389,2020-01-07T16:38:04Z,2020-01-07T16:38:04Z,MEMBER,"it does. Also, no errors in either case, so the problem is with `DatetimeIndex`, `CFTimeIndex` or the way the data is converted.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,546303413
https://github.com/pydata/xarray/issues/3666#issuecomment-571665270,https://api.github.com/repos/pydata/xarray/issues/3666,571665270,MDEyOklzc3VlQ29tbWVudDU3MTY2NTI3MA==,2448579,2020-01-07T16:33:06Z,2020-01-07T16:33:06Z,MEMBER,I'm guessing `decode_times=False` will fix that bit.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,546303413
https://github.com/pydata/xarray/issues/3666#issuecomment-571639956,https://api.github.com/repos/pydata/xarray/issues/3666,571639956,MDEyOklzc3VlQ29tbWVudDU3MTYzOTk1Ng==,14808389,2020-01-07T15:38:57Z,2020-01-07T15:38:57Z,MEMBER,"I can reproduce this error with your files:
```python
In [18]: files = glob.glob(""*.nc"") 
    ...: datasets = [xr.open_dataset(file) for file in files] 
    ...: xr.concat(datasets, dim=""new_dim"")
RecursionError
```
but sorting the files before concatenating results in a different error:
```python
In [19]: files = glob.glob(""*.nc"") 
    ...: datasets = [xr.open_dataset(file) for file in sorted(files)] 
    ...: xr.concat(datasets, dim=""new_dim"")
TypeError: cannot compare cftime.DatetimeNoLeap(1950-01-01 00:00:00) and Timestamp('1950-01-01 00:00:00') (different calendars)
```
which might mean that there is a problem with the data.

Regardless, we might want to make sure the recursion does not happen.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,546303413
https://github.com/pydata/xarray/issues/3666#issuecomment-571639751,https://api.github.com/repos/pydata/xarray/issues/3666,571639751,MDEyOklzc3VlQ29tbWVudDU3MTYzOTc1MQ==,2448579,2020-01-07T15:38:28Z,2020-01-07T15:38:28Z,MEMBER,"Thanks @tlogan2000.

Can you reduce this example to just a `xarray.concat` call?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,546303413