issue_comments: 332934061

cc @thenaomig @laliberte

There are at least two ways to fix this: 1. Support a flag of some sort in encoding (e.g., _FillValue = False) to indicate that fill value shouldn't be added. This would be easy to add, but is somewhat inelegant. 2. Check for the presence of NaNs before setting _FillValue = NaN. This would be easy to add for dimension coordinates because they are already guaranteed to be in memory, but could cause performance trouble if any inputs are loaded as dask arrays. I don't know a satisfactory way to handle dask arrays with our current design, since we don't want to add another pass over the data to check for NaNs. I suppose one option would be to refactor our backend classes to write data before writing attributes and then make some sort of dask array operation that checks for NaNs as the data is written. But I'm not even sure this would work with the standard dask task schedulers.