There's a merged pull request on the void-packages repository

git: correct utf-16 and utf-32 conversion on musl
https://github.com/void-linux/void-packages/pull/15943

Description:
musl's iconv treats utf-{16,32} encoding as utf-{16,32}be,
without BOM, correctly according to POSIX.

However, most tools out there think differently.

Change the build flag for the musl system to fix it.

Together with my patch here:
https://github.com/git/git/commit/840c40cea11290d40fd455cc3b23d5793056f4d4

git's test: t0028 should be fine now.