FastHerbie xarray issue on sfc product

[danielabdi-noaa]

Trying to use FastHerbie like this

H = FastHerbie(
    timestamps,
    model="hrrr",
    product="sfc",
    save_dir="./.herbie-grib",
    fxx=self.fxx,
)

I get an error in fast.py due to a missing "step" coordinate I think.

2024-09-08 11:05:31,293 -INFO - 🧵 Working on 3 tasks with 3 threads.
2024-09-08 11:05:31,732 -INFO - Number of Herbie objects: 3
Traceback (most recent call last):
  File "/home/daniel/storage/hrrrdata/data/preprocess.py", line 43, in <module>
    preprocess_hrrr()
  File "/home/daniel/storage/hrrrdata/data/preprocess.py", line 30, in preprocess_hrrr
    ds = hds.open_dataset(start, end, freq)
  File "/home/daniel/storage/hrrrdata/data/get_data_hrrr.py", line 64, in open_dataset
    ds2 = H.xarray(
  File "/home/daniel/miniconda3/envs/hrrrcast/lib/python3.10/site-packages/herbie/fast.py", line 303, in xarray
    ds_list.sort(key=lambda x: x.step.data.max())
  File "/home/daniel/miniconda3/envs/hrrrcast/lib/python3.10/site-packages/herbie/fast.py", line 303, in <lambda>
    ds_list.sort(key=lambda x: x.step.data.max())
AttributeError: 'list' object has no attribute 'step'