Bug#1041164: dose-distcheck: fails with (W)Dose_common: package ncurses-base:amd64 (= 6.4-4) is not associate with an integer in the given universe"

[Ralf Treinen <treinen@irif.fr>]

For the record : this seems to be related to the option "--latest 1"
discarding Essential packages. Here is a minimal Packages file for
reproducing the bug:

Package: aa
Source: aa
Version: 1
Essential: yes
Architecture: all

Package: aa
Source: aa
Version: 2
Architecture: all

-Ralf.