In case anyone is interested, I filed a bug report for APT: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=948735
>postgresql-client-11 sounds like a bug but the dev seems to be ignoring it. >postgresql-common I found this: https://www.postgresql.org/message-id/cabuevewgx16f-%2bwpk-rkh%2brufgcpveg0xjcwazoobyzka_j...@mail.gmail.com