Function fchownat 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn fchownat(
    fd: c_int,
    path: *const c_char,
    owner: uid_t,
    group: gid_t,
    flags: c_int,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/fchownat.html.