Error when using mizutil.to_bmorph function without met data

[nmizukami]

I would like to execute to_bmorph function without met_hru data. met_hru in mizutil.to_bmorph is optional. When I execute this without met_hru:

yakima_met_seg = mizutil.to_bmorph(yakima_topo, routed=yakima_raw, reference=yakima_ref, fill_method='r2')

it complains here:

File ~/model/bmorph/bmorph/util/mizuroute_utils.py:997, in to_bmorph(topo, routed, reference, met_hru, route_var, fill_method, min_kge)
    994 met_vars = set(met_hru.variables.keys()) - set(met_hru.coords)
    996 # Remap any meteorological data from hru to stream segment
--> 997 met_seg = map_met_hru_to_seg(met_hru, topo)
    998 # flag whether each seg has an
    999 # hru or not as a requirement for bias correction
   1000 hru_2_seg = topo['seg_hru_id'].values

File ~/model/bmorph/bmorph/util/mizuroute_utils.py:910, in map_met_hru_to_seg(met_hru, topo)
    906 # Map from hru -> segment for met data
    907 # In case a segment is not assigned an hru,
    908 # nan fills the place of any conditioning data
    909 segs_without_hrus = []
--> 910 for seg in met_seg['seg'].values:
    911     subset = np.argwhere(hru_2_seg == seg).flatten()
    912     if not len(subset):

met_seg does not 'seg' key value. line 994 set operation gives empty set if you do not provide met_hru. I am not sure if I am missing or misunderstand something, but any thoughts?