Okay, did not expect that Heinrich's change also causes regressions on autopkgtests infra. When I gave him my original also-not-working workaround I told him it had problems when ran on autopkgtests, so when he came up with this solution instead I thought it was tested on autopkgtest environment and this is why he proposed it. My bad for not giving it a spin in some bileto PPA before merging, yay for just assuming stuff.
Okay, did not expect that Heinrich's change also causes regressions on autopkgtests infra. When I gave him my original also-not-working workaround I told him it had problems when ran on autopkgtests, so when he came up with this solution instead I thought it was tested on autopkgtest environment and this is why he proposed it. My bad for not giving it a spin in some bileto PPA before merging, yay for just assuming stuff.