Package: hostname Version: 3.22 Size of buffer (buf) for all FQDN's is limited to 255 octets thus maximum size of getnameinfo() output is 254 octets + '\0' while RFC [1] specifies it to be 255 octets. Easiest fix would be to increase buffer size to 256 but getnameinfo(3) suggests to use char buf[NI_MAXHOST]; instead.
[1] - https://tools.ietf.org/html/rfc1035#section-2.3.4