For Zarr 2.18.3 ```python zarr.create(shape=10, dtype=str).dtype # -> dtype('O') ``` For `v3` branch @ 5a134bf2c1c5e6655edd429ca554aa9699327463 ```python 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