GitLab

Parent issue: tails#17842

Having isotesters running Stretch, instead of Buster, blocks:

• tails#15450
• tails#15831
• tails#15330
• tails#17031
• dropping some Stretch backwards compatibility code in our test suite

Additionally, this would allow me to maintain 1 custom QEMU package (Buster) instead of 2 (Stretch and Buster): the current situation, introduced by tails#15460 (closed), was meant to be very temporary, as per the discussion on tails#17457 (comment 2437), where @anonym and I agreed we should notify sysadmins ASAP about our need for this upgrade; but apparently we closed the issue without communicating about this :/

Setting milestone to 2020 as per the "Upgrade our systems to Buster" item in sysadmins' roadmap-2019Q3-2020Q2.mdwn.