Fix error message (#3076)
Fix error message (#3076)


shoyer/xarray,pydata/xarray,markelg/xray,xray/xray,jhamman/xray,markelg/xray,jhamman/xarray,jhamman/xarray,pydata/xarray,jhamman/xarray,markelg/xray,pydata/xarray,shoyer/xarray