python-zarr fails to build with Python 3.10.0b1:

...
E       TypeError: initializer for ctype 'char *' must be a cdata pointer, not numpy.ndarray
/usr/lib64/python3.10/site-packages/lmdb/cffi.py:1438: TypeError
...
E       TypeError: len() of unsized object
/usr/lib64/python3.10/site-packages/lmdb/cffi.py:1439: TypeError
...
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStore::test_array_0d - TypeE...
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStore::test_compressors - Ty...
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStore::test_iteration_exceptions
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStore::test_store_has_binary_values
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStore::test_store_has_text_keys
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStoreNoBuffers::test_array_0d
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStoreNoBuffers::test_compressors
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStoreNoBuffers::test_iteration_exceptions
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStoreNoBuffers::test_store_has_binary_values
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStoreNoBuffers::test_store_has_bytes_values
FAILED zarr/tests/test_core.py::TestArrayWithLMDBStoreNoBuffers::test_store_has_text_keys
FAILED zarr/tests/test_hierarchy.py::TestGroupWithLMDBStore::test_move - Type...
FAILED zarr/tests/test_hierarchy.py::TestGroupWithLMDBStore::test_setitem - T...
FAILED zarr/tests/test_storage.py::TestLMDBStore::test_writeable_values - Typ...
==== 14 failed, 1924 passed, 367 skipped, 2 xfailed, 11 warnings in 54.41s =====

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.10/fedora-rawhide-x86_64/02172746-python-zarr/

For all our attempts to build python-zarr with Python 3.10, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.10/package/python-zarr/

Testing and mass rebuild of packages is happening in copr. You can follow these instructions to test locally in mock if your package builds with Python 3.10:
https://copr.fedorainfracloud.org/coprs/g/python/python3.10/

Let us know here if you have any questions.

Python 3.10 will be included in Fedora 35. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.10.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires), so if this package is required a lot, it's important for us to get it fixed soon.
We'd appreciate help from the people who know this package best, but if you don't want to work on this now, let us know so we can try to work around it on our side.