Bigendian support was dropped in c-blosc2 3.2.3-1~exp1
but it ought to be fixed now in v3, at least for ppc64.

ppc64 support was patched in upstream PR#723
https://github.com/Blosc/c-blosc2/pull/723

It sets specific definitions when __BIG_ENDIAN__ is defined,
albeit under _ARCH_PWR8 for ppc64.

Can an equivalent patch for __BIG_ENDIAN__ code
(setting BLOSC_BPERM_RESULT_IDX) work in the code path used for s390x?
(I guess that would be patching blosc/bitshuffle-generic.c)

Thanks Drew,
I can give it a try after the current migration is complete.

As DM I do not have direct access to the HW, I will ask for a temporary
authorization.

By the way the issue number in your message seems not to be correct.
I understand that the correct one is
https://github.com/Blosc/c-blosc2/issues/702, correct?

For the record, another relevant upstream issue is
https://github.com/Blosc/c-blosc2/issues/467.

kind regards