my $known_versions = {
'26.04' => 1, # r LTS
'25.10' => 1, # questing
'25.04' => 1, # plucky
'24.10' => 1, # oracular
'24.04' => 1, # noble LTS
'23.10' => 1, # mantic
'23.04' => 1, # lunar
'22.10' => 1, # kinetic
'22.04' => 1, # jammy LTS
'21.10' => 1, # impish
'21.04' => 1, # hirsute
'20.10' => 1, # groovy
'20.04' => 1, # focal LTS
'19.10' => 1, # eoan
'19.04' => 1, # disco
'18.10' => 1, # cosmic
'18.04' => 1, # bionic LTS
'17.10' => 1, # artful
'17.04' => 1, # zesty
# TODO: actively drop below entries that ship with systemd, as their version is to old for CGv2
'16.10' => 1, # yakkety
'16.04' => 1, # xenial LTS
'15.10' => 1, # wily
'15.04' => 1, # vivid
'14.04' => 1, # trusty LTS
'12.04' => 1, # precise LTS
};