Removals keep removing dependencies if removal of a package fails

[Julian Andres Klode]

[Impact]

Assuming packages A and B, with A depending on B. A has a failing prerm script.

Expected behavior:
- A fails to be removed, A and B stay unchanged
Actual behavior:
- A fails to be removed
- B is still removed

This might crash their system (e.g. if A is systemd and B is libsystemd0).

[Test case]
See Impact. An automated version of the test case (test-apt-get-remove-depends) is included and run on autopkgtest.

[Regression potential]
We now abort earlier in removal failures, that might be harder to recover from or not, nobody really knows.

[Launchpad Janitor (janitor)]

This bug was fixed in the package apt - 1.9.4

---------------
apt (1.9.4) experimental; urgency=medium

  * CMake: Pass -Werror=return-type to gcc
  * CMake: Produce a fatal error if triehash could not be found
  * apt.systemd.daily: Do not numerically check if intervals equal 0
    (LP: #1840995)
  * srvrec: Use re-entrant resolver functions
  * Pass --abort-after=1 to dpkg when using --force-depends (Closes: #935910)
    (LP: #1844634)
  * Fix use of GTest to adjust for GTest 1.9

 -- Julian Andres Klode <email address hidden> Thu, 19 Sep 2019 11:13:47 +0200

[Steve Langasek (vorlon)]

Hello Julian, or anyone else affected,

Accepted apt into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/apt/1.8.4 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted apt (1.8.4) for disco have finished running.
The following regressions have been reported in tests triggered by the package:

reprotest/0.7.8 (s390x)
gcc-snapshot/unknown (armhf)
apt/1.8.4 (amd64, armhf, s390x, ppc64el, arm64, i386)
autopkgtest/5.10ubuntu1 (amd64, i386)
gcc-7/7.4.0-8ubuntu1 (armhf)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/disco/update_excuses.html#apt

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!