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/3409#issuecomment-551142493,https://api.github.com/repos/pydata/xarray/issues/3409,551142493,MDEyOklzc3VlQ29tbWVudDU1MTE0MjQ5Mw==,6213168,2019-11-07T15:59:01Z,2019-11-07T15:59:01Z,MEMBER,"@dcherian I didn't try running the PR code, but I don't think so?
The PR *may* mean (must test) that nanmin() and nanmax() now work with NaT. However, as highlighted above https://github.com/pydata/xarray/issues/3409#issuecomment-544299242 xarray is invoking min() on an array that contains NaT - which in numpy 1.17 ignores them, while in 1.18 correctly returns NaT.

Does anybody have the time to test it?
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922
https://github.com/pydata/xarray/issues/3409#issuecomment-547625012,https://api.github.com/repos/pydata/xarray/issues/3409,547625012,MDEyOklzc3VlQ29tbWVudDU0NzYyNTAxMg==,6213168,2019-10-29T20:54:42Z,2019-10-29T20:54:42Z,MEMBER,"Same problem:
```python
a = xarray.DataArray(['1999-12-15', 'NaT']).astype('M8[ns]')            
a.min(skipna=False)  # np 1.17: 1999-12-15; np 1.18: NaT
a.min(skipna=True)  # np 1.17: crashes; np 1.18: crashes
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922
https://github.com/pydata/xarray/issues/3409#issuecomment-544299242,https://api.github.com/repos/pydata/xarray/issues/3409,544299242,MDEyOklzc3VlQ29tbWVudDU0NDI5OTI0Mg==,6213168,2019-10-20T22:25:00Z,2019-10-20T22:32:34Z,MEMBER,"Narrowed down:
```python
>>> import numpy as np
>>> a = np.array(['1999-12-15', 'NaT'], dtype='M8[ns]')
>>> np.min(a)
```
Output:
numpy 1.17: ``numpy.datetime64('1999-12-15T00:00:00.000000000')``
numpy 1.18: ``numpy.datetime64('NaT')``

triggered by:
https://github.com/pydata/xarray/blob/0f7ab0e909d9b6272f734a0b6fa4318e9522d3a2/xarray/core/duck_array_ops.py#L372
","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922
https://github.com/pydata/xarray/issues/3409#issuecomment-544294825,https://api.github.com/repos/pydata/xarray/issues/3409,544294825,MDEyOklzc3VlQ29tbWVudDU0NDI5NDgyNQ==,6213168,2019-10-20T21:31:25Z,2019-10-20T21:31:25Z,MEMBER,"Looking more closely at the failing tests, there are actually two problems.
One is with pandas/numpy git tip, and it only affects the upstream-dev test suite.
The other is with pseudonetcdf-3.1, and it affects py36, py37, and upstream-dev.

","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922
https://github.com/pydata/xarray/issues/3409#issuecomment-544292376,https://api.github.com/repos/pydata/xarray/issues/3409,544292376,MDEyOklzc3VlQ29tbWVudDU0NDI5MjM3Ng==,6213168,2019-10-20T21:03:19Z,2019-10-20T21:03:19Z,MEMBER,"It doesn't add up - the upstream ticket mentions an incompatibility with numpy 1.18. However, our failing tests are all running with numpy 1.17.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922
https://github.com/pydata/xarray/issues/3409#issuecomment-544263042,https://api.github.com/repos/pydata/xarray/issues/3409,544263042,MDEyOklzc3VlQ29tbWVudDU0NDI2MzA0Mg==,6213168,2019-10-20T15:32:17Z,2019-10-20T15:35:01Z,MEMBER,"conda list (py36) before and after the breakage:
```
< boto3                     1.9.252                    py_0    conda-forge
> boto3                     1.9.253                    py_0    conda-forge
< botocore                  1.12.252                   py_0    conda-forge
> botocore                  1.12.253                   py_0    conda-forge
< expat                     2.2.5             he1b5a44_1003    conda-forge
> expat                     2.2.5             he1b5a44_1004    conda-forge
< libxkbcommon              0.8.4                h516909a_0    conda-forge
> libxkbcommon              0.9.0                hebb1f50_0    conda-forge
< mypy_extensions           0.4.2                    py36_0    conda-forge
> mypy_extensions           0.4.3                    py36_0    conda-forge
< nss                       3.46                 he751ad9_0    conda-forge
> nss                       3.47                 he751ad9_0    conda-forge
< pandas                    0.25.1           py36hb3f55d8_0    conda-forge
> pandas                    0.25.2           py36hb3f55d8_0    conda-forge
< pip                       19.3                     py36_0    conda-forge
> pip                       19.3.1                   py36_0    conda-forge
< pseudonetcdf              3.0.2                      py_0    conda-forge
> pseudonetcdf              3.1.0                      py_0    conda-forge
```","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922
https://github.com/pydata/xarray/issues/3409#issuecomment-544262623,https://api.github.com/repos/pydata/xarray/issues/3409,544262623,MDEyOklzc3VlQ29tbWVudDU0NDI2MjYyMw==,6213168,2019-10-20T15:27:40Z,2019-10-20T15:34:41Z,MEMBER,This has now spread to all tests without pinned dependencies,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,508167922