For Zarr 2.18.3
zarr.create(shape=10, dtype=str).dtype
# -> dtype('O')
For v3
branch @ 5a134bf
zarr.create(shape=10, dtype=str, zarr_version=2).dtype
# -> dtype('<U')
This is causing problems in Xarray for string compatibility.
Might have been broken by #2036
cc @TomAugspurger