Bug#1104671: python3-zarr: fails on big-endian archs, causing xarray to break

[Antonio Valentino]

Dear Julian,

On Sun, 04 May 2025 11:30:18 +0100 Julian Gilbey <jdg at debian.org> wrote:
> Package: python3-zarr
> Version: 3.0.6-1
> Severity: serious
> X-Debbugs-Cc: Antonio Valentino <antonio.valentino at tiscali.it>
> 
> The python-xarray autopkgtest is failing on s390x, because the arch is
> big-endian and so the lookup for the dtype in from_numpy fails;
> zarr/core/metadata/v3.py only lists in dtype_to_data_type, for
> example, "<i8" and not ">i8".
> 
> I think the solution to this is simply to add the equivalent
> big-endian dtypes to this dict.
> 
> I'll do a team upload with this change later today, as this is causing
> a lot of potential autorms.
> 
> Best wishes,
> 
>    Julian

AFAIK the version of zarr v3 currently in debian does not support BE 
architectures.

Support for BE will be probably available in Zarr v3.1 (not an option 
for trixie).

It is not clear to me what kind of patch you want to propose for zarr, 
but a common workaround for the client code (xarray in this case) is to 
force the numpy "in-memory" representation to LE before storing it into 
zarr.

Kind regards
-- 
Antonio Valentino