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/2037#issuecomment-1063906458,https://api.github.com/repos/pydata/xarray/issues/2037,1063906458,IC_kwDOAMm_X84_aeya,47473455,2022-03-10T10:35:23Z,2022-03-10T10:59:17Z,NONE,"I see know why it did not had sense to push something. Basically cf requirements are in conflict with backend requirements.
It would be needed to restructure tests and review which from backend have sense to apply.
```py
======================================================== short test summary info ========================================================
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_write_store - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_write_store - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_ondisk_after_print - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_vectorized_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_isel_dataarray - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_roundtrip_test_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_roundtrip_timedelta_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_isel_dataarray - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_load - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_write_store - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_coordinate_variables_after_dataset_roundtrip - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_roundtrip_numpy_datetime_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_roundtrip_test_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_orthogonal_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_dataset_compute - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_roundtrip_timedelta_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_zero_dimensional_variable - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_dataset_compute - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_array_type_after_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_append_write - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_vectorized_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_coordinate_variables_after_dataset_roundtrip - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_isel_dataarray - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_append_overwrite_values - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_load - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_grid_mapping_and_bounds_are_coordinates_after_dataarray_roundtrip - Ke...
FAILED xarray/tests/test_backends.py::TestGenericNetCDFData::test_cross_engine_read_write_netcdf3 - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_vectorized_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_grid_mapping_and_bounds_are_coordinates_after_dataarray_roundtrip - ...
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_append_overwrite_values - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_zero_dimensional_variable - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_ondisk_after_print - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_roundtrip_timedelta_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_append_with_invalid_dim_raises - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_orthogonal_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_array_type_after_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_orthogonal_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_append_with_invalid_dim_raises - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_roundtrip_numpy_datetime_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_zero_dimensional_variable - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_roundtrip_test_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_append_write - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_ondisk_after_print - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_roundtrip_numpy_datetime_data - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_dataset_compute - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_append_write - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_load - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_array_type_after_indexing - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestGenericNetCDFData::test_engine - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_grid_mapping_and_bounds_are_coordinates_after_dataarray_roundtrip - KeyE...
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_coordinate_variables_after_dataset_roundtrip - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_append_with_invalid_dim_raises - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_append_overwrite_values - KeyError: ('O', 8)
FAILED xarray/tests/test_backends.py::test_scipy_entrypoint - KeyError: ('O', 8)
```

However your snipet worked, but it is not applying to boundary variables, which is a cf requirement as well.
Probably I would edit it to something like:
```py
    # remove _FillValue for coordinate variables as missing values are not permitted (issue #2037)
    # a coordinate variable is a one-dimensional variable with the same name as its dimension
    # see coordinate variable in http://cfconventions.org/cf-conventions/cf-conventions.html#terminology
    for var in new_vars.keys():
        if new_vars[var].dims == (var,):
            new_vars[var].attrs[""_FillValue""] = None
            if ""bounds"" in new_vars[var].attrs:
                bnds = new_vars[var].attrs['bounds']
                new_vars[bnds].attrs[""_FillValue""] = None 
```
I will create a PR with the hope a developer will take a look into this.
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,310833761
https://github.com/pydata/xarray/issues/2037#issuecomment-1063806501,https://api.github.com/repos/pydata/xarray/issues/2037,1063806501,IC_kwDOAMm_X84_aGYl,47473455,2022-03-10T08:44:15Z,2022-03-10T08:44:15Z,NONE,"> @BorjaEst I haven't opened a PR for this slightly_smiling_face

@ellesmith88 is there a branch/fork where you implemented your trials or shall I start one and add your code?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,310833761
https://github.com/pydata/xarray/issues/2037#issuecomment-1063707401,https://api.github.com/repos/pydata/xarray/issues/2037,1063707401,IC_kwDOAMm_X84_ZuMJ,47473455,2022-03-10T06:24:58Z,2022-03-10T06:25:12Z,NONE,"@ellesmith88 [ellesmith88](https://github.com/ellesmith88)
> but I couldn't quite get this to work, with some tests in test_backends.py failing. I could see that the fill value is being added in by maybe_default_fill_value in conventions.py so maybe it would be better to skip coordinate variable and bounds here. I can't really spend anymore time on this but putting it here in case its useful.

I see you are setting `_FillValue` to `None` but probably it should be set to `False` instead.
See https://stackoverflow.com/questions/45693688/xarray-automatically-applying-fillvalue-to-coordinates-on-netcdf-output

I can give it a try. In which PR are you working on this?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,310833761
https://github.com/pydata/xarray/issues/2037#issuecomment-1063705114,https://api.github.com/repos/pydata/xarray/issues/2037,1063705114,IC_kwDOAMm_X84_Ztoa,47473455,2022-03-10T06:20:40Z,2022-03-10T06:20:40Z,NONE,"I am posting here a temporal solution to this in case someone has the same issue.
Based on https://stackoverflow.com/questions/45693688/xarray-automatically-applying-fillvalue-to-coordinates-on-netcdf-output
```py
for var in ds.variables:
    if '_FillValue' not in ds[var].attrs:
        ds[var].attrs['_FillValue'] = False
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,310833761