@edwintorok POSIX does not mandate that format for 12 leading zero bytes, but several implementations do it as RFC 4291 suggests. @musl makes no attempt to: https://git.musl-libc.org/cgit/musl/tree/src/network/inet_ntop.c?h=v1.2.3
As I want a stable behavior for curl, I need the same output independently of libc...