Bug#984574: gcc-10-base: please add Breaks: gcc-8-base (<< 8.4)

[Andreas Beckmann <anbe@debian.org>]

Package: gcc-10-base
Version: 10.2.1-6
Severity: serious
User: debian-qa@lists.debian.org
Usertags: piuparts

Hi,

while investigating some buster->bullseye upgrade failures in piuparts I
came across a case where apt tries to keep libstdc++-8-dev installed to
satisfy the libstdc++-dev dependency of some boost package.
Adding a versioned
  Breaks: gcc-8-base (<< 8.4)
should ensure the full gcc-8 stack from buster gets removed during the
upgrade (while systems running testing/unstable that still have a newer
version of gcc-8 installed would be able to keep that installed).
We had similar fixes for previous releases as well.

Andreas