Variables from cube are missing

[gdkrmr]

Some variables from some of the cubes are missing:

julia> c = Cube("/home/gkraemer/data/DataCube/v2.1.0/esdc-8d-0.083deg-184x270x270-2.1.0.zarr/")
julia> setdiff(readdir("/home/gkraemer/data/DataCube/v2.1.0/esdc-8d-0.083deg-184x270x270-2.1.0.zarr/"), getAxis("Variable", c).values)
19-element Vector{String}:
 ".zattrs"
 ".zgroup"
 ".zmetadata"
 "aerosol_optical_thickness_1600"
 "aerosol_optical_thickness_550"
 "aerosol_optical_thickness_670"
 "aerosol_optical_thickness_870"
 "analysed_sst"
 "lat"
 "lat_bnds"
 "lon"
 "lon_bnds"
 "mask"
 "sea_ice_fraction"
 "sm"
 "time"
 "time_bnds"
 "xch4"
 "xco2"