[pkg-netfilter-team] Bug#969058: iptables in buster-backports requires netbase >= 6.0 which is not present in archive

[Johan Fleury]

Package: iptables
Version: 1.8.5-3~bpo10+1
Severity: grave
Justification: renders package unusable

Dear Maintainer,

Commit d7ad2173[^1] was backported into the debian/buster-backports
branch and the iptables package version 1.8.5-3~bpo10+1 was pushed to
the buster-backports archive yesterday[^2], but netbase is not present
in version >=6.0 in the archive.

This makes `iptables` un-upgradable on my system, and even worse, it
lead to it being removed an I cannot install it anymore:

```
Start-Date: 2020-08-26  19:32:52
Commandline: /usr/bin/apt-get --option=Dpkg::Options::=--force-confold --option=Dpkg::options::=--force-unsafe-io --assume-yes --quiet dist-upgrade
Upgrade: libip6tc2:amd64 (1.8.3-2~bpo10+1, 1.8.5-3~bpo10+1), libiptc0:amd64 (1.8.3-2~bpo10+1, 1.8.5-3~bpo10+1), libxtables12:amd64 (1.8.3-2~bpo10+1, 1.8.5-3~bpo10+1), libip4tc2:amd64 (1.8.3-2~bpo10+1, 1.8.5-3~bpo10+1)
Remove: iptables:amd64 (1.8.3-2~bpo10+1), kubernetes-worker:amd64 (1.18.8-1), ufw:amd64 (0.36-1), docker-ce:amd64 (5:19.03.12~3-0~debian-buster)
End-Date: 2020-08-26  19:32:56
```

iptables is installed from buster-backports using the folowing
preference configuration:

```
Package: iptables libiptc0 libnftnl11 libxtables12
Pin: release a=buster-backports
Pin-Priority: 1001
```

[^1]: https://salsa.debian.org/pkg-netfilter-team/pkg-iptables/-/commit/d7ad2173f0cd7d26d2ecf0b49d3708203973faf2
[^2]: https://salsa.debian.org/pkg-netfilter-team/pkg-iptables/-/commit/f9ad7966a634ec0700f81f19bfb03fdfa8a09cdd

-- System Information:
Debian Release: 10.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-10-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages iptables depends on:
ii  libc6                    2.28-10
ii  libip4tc0                1.8.2-4
ii  libip4tc2                1.8.5-3~bpo10+1
ii  libip6tc0                1.8.2-4
ii  libip6tc2                1.8.5-3~bpo10+1
ii  libiptc0                 1.8.5-3~bpo10+1
ii  libmnl0                  1.0.4-2
ii  libnetfilter-conntrack3  1.0.7-1
ii  libnfnetlink0            1.0.1-3+b1
ii  libnftnl11               1.1.7-1~bpo10+1
ii  libxtables12             1.8.5-3~bpo10+1
ii  netbase                  5.6

Versions of packages iptables recommends:
pn  nftables  <none>

Versions of packages iptables suggests:
pn  firewalld  <none>
ii  kmod       26-1