The _FillValue attribute is added in output datasets by xarray.open_zarr (the option mask_and_scale is turned off, as zarr's fill value that defaults to 0 for numeric dtypes causes other issues).
The problem is for string-like dtypes. It looks like empty string as attribute value is not supported with netCDF serialization.
The
_FillValueattribute is added in output datasets byxarray.open_zarr(the optionmask_and_scaleis turned off, as zarr's fill value that defaults to 0 for numeric dtypes causes other issues).The problem is for string-like dtypes. It looks like empty string as attribute value is not supported with netCDF serialization.