download failing for RFC-5 CoordinateSystems group

[dstansby]

I'm trying to download a dataset, and getting the following error:

% ome_zarr download https://uk1s3.embassy.ebi.ac.uk/idr/zarr/test-data/v0.6dev2/idr0067/9036345_tiles.zarr
Traceback (most recent call last):
  File "/Users/dstansby/software/ome-zarr/ome-zarr-napari/.venv/bin/ome_zarr", line 10, in <module>
    sys.exit(main())
             ~~~~^^
  File "/Users/dstansby/software/ome-zarr/ome-zarr-napari/.venv/lib/python3.13/site-packages/ome_zarr/cli.py", line 210, in main
    ns.func(ns)
    ~~~~~~~^^^^
  File "/Users/dstansby/software/ome-zarr/ome-zarr-napari/.venv/lib/python3.13/site-packages/ome_zarr/cli.py", line 50, in download
    zarr_download(args.path, args.output)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/dstansby/software/ome-zarr/ome-zarr-napari/.venv/lib/python3.13/site-packages/ome_zarr/utils.py", line 326, in download
    common = strip_common_prefix(paths)
  File "/Users/dstansby/software/ome-zarr/ome-zarr-napari/.venv/lib/python3.13/site-packages/ome_zarr/utils.py", line 408, in strip_common_prefix
    min_length = min(len(x) for x in parts)
ValueError: min() iterable argument is empty

[will-moore]

Thanks for reporting - I think the issue there is that the 9036345_tiles.zarr group doesn't contain multiscales and the download code hasn't been updated to work with the RFC5 sample data.

Similar issue to #494 - Download needs the reader code to iterate over every multiscales group as a separate Node.

[allison-truhlar]

Hi, I get the same error as reported above for these datasets as well:
https://uk1s3.embassy.ebi.ac.uk/idr/zarr/v0.5/idr0033A/BR00109990_C2.zarr/
https://uk1s3.embassy.ebi.ac.uk/idr/zarr/v0.4/idr0079A/idr0079_images.zarr