This could have been prevented (or at least be detected more easily) with a .symbols file. I have eadded one based upon a fresh build in a wheezy/i386 chroot. Severalsymbols are missing when rebuilding on stretch/i386:
--- debian/libnids1.21.symbols (libnids1.21_1.23-2_i386) +++ dpkg-gensymbolsEzWosP 2017-02-26 14:39:17.620478840 +0000 @@ -1,19 +1,19 @@ libnids.so.1.21 libnids1.21 #MINVER# - after@Base 1.23 - before@Base 1.23 +#MISSING: 1.23-2# after@Base 1.23 +#MISSING: 1.23-2# before@Base 1.23 csum_partial@Base 1.23 detect_scan@Base 1.23 find_stream@Base 1.23 init_hash@Base 1.23 - ip_compute_csum@Base 1.23 +#MISSING: 1.23-2# ip_compute_csum@Base 1.23 ip_defrag_stub@Base 1.23 - ip_fast_csum@Base 1.23 +#MISSING: 1.23-2# ip_fast_csum@Base 1.23 ip_frag_exit@Base 1.23 ip_frag_init@Base 1.23 ip_options_compile@Base 1.23 mkhash@Base 1.23 - my_tcp_check@Base 1.23 - my_udp_check@Base 1.23 +#MISSING: 1.23-2# my_tcp_check@Base 1.23 +#MISSING: 1.23-2# my_udp_check@Base 1.23 nids_discard@Base 1.23 nids_dispatch@Base 1.23 nids_errbuf@Base 1.23 Cheers, -Hilko
