snac 2.89 がDebian stable-backports に降りてきた
ただしriscv64 を除く

$ rmadison snac2 -s stable-backports
snac2 | 2.88-1~bpo13+1 | stable-backports | source, riscv64
snac2 | 2.89-1~bpo13+1 | stable-backports | source, amd64, arm64, armel, armhf, i386, ppc64el, s390x

https://tracker.debian.org/news/1713542/accepted-snac2-289-1bpo131-source-into-stable-backports/