On 2024-11-04 18:29, Paride Legovini wrote: > *However*, if you check the policy table at this point, it will > identical to the previous one. APT has no way to determine the real > source of an installed package: it only knows about _versions_ of > installed packages. [Note how /var/lib/dpkg/status, which contains info > on the installed packages, has no SHA256 for packages.] > > Not knowing better, APT assumes that that an installed package comes > from the *first* APT source that provides that version.
APT resorts to this if all the other fields in /var/lib/dpkg/status do not allow to disambiguate the source of the installed package. The fields that count are [1]: Installed-Size Depends Pre-Depends Conflicts Breaks Replaces I tried testing src:gzip from trixie and it worked fine, the "disambiguating field" being: +Installed-Size: 246 -Installed-Size: 250 Now, if we can think of a good way to disambiguate any of those fields before the autopkgtest build, we have a fix for this bug. Just to verify this is sound, I added a Conflicts: autopkgtest-disambiguate to bin:libselinux1 in my local source tree, and this resolved the issue. Cheers, Paride [1] https://salsa.debian.org/apt-team/apt/-/blob/bc1fbd12789bfebf225be7af5052840a6add21e2/apt-pkg/deb/deblistparser.cc#L336
