Debian dist-upgrade test does not work when new dependencies are introduced

In order to keep dist-upgrade limited to MariaDB only, to avoid lengthy system-wide upgrades, after initial installation the test removes from sources.list everything, except for the local repo. Normally it works fine, because a previous minor version has already been installed. So, it also serves as an additional check that no new dependencies have been introduced, because normally a minor upgrade should not bring any.

But pre-GA versions are allowed to have new dependencies, e.g. current 10.2.3 wants libnuma1, which cannot be installed without default repos, so the test fails.

https://internal.askmonty.org/buildbot/builders/kvm-deb-jessie-amd64/builds/1394/steps/test_3/logs/stdio

Calculating upgrade... Done

The following NEW packages will be installed:

  libmariadb3

The following packages will be upgraded:

  libmariadbclient18 libmysqlclient18 mariadb-client-10.2

  mariadb-client-core-10.2 mariadb-common mysql-common

6 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.

Ideally, it would be good to find a smarter way to limit dist-upgrade than to remove all repos from the list. Pinning repos with low priority isn't simple because we don't know in advance which exact repos are present on the list, so it might require some tricky parsing. It should be doable though if there is no other way.