cryptsetup-initramfs disappeared during upgrade from 23.10 to 24.04 leading to failing boot

[Beda Kosata]

[Impact]

If an upgrade removes cryptsetup-initramfs, the system can then fail to boot.

[Test Plan]

We don't currently have a reproducer for this scenario, so we need to test that cryptsetup-initramfs is listed in the removal_denylist.cfg during upgrades to Noble.

1. Start an upgrade

$ do-release-upgrade

2. In another terminal, after the tarball has been downloaded and unpacked, find the temp directory

$ tmpdir="$(find /tmp -name ubuntu-release-upgrader-* -type d)"

3. Check that cryptsetup-initramfs is in the removal deny list:

grep "cryptsetup-initramfs" "$tmpdir/removal_denylist.cfg"

It should be listed there.

[Where problems could occur]

If there was a typo in the patch, the entry would not correctly match the cryptsetup-initramfs package name, and would therefore not prevent removal during upgrades.

[Original Description]

I have a system with a full-disk encryption installed with 23.10. After doing an upgrade to 24.04 from command line using `do-release-upgrade` (everything went without a problem), I rebooted and got a initramfs prompt complaining about root filesystem not being available.

I was able to boot using the kernel from the previous version (6.5.0) and after inspecting the system, I found that the `cryptsetup-initramfs` package was not installed. After installing it, it produced a new and slightly larger initramfs. With it, I was able to boot with the 6.8.0 kernel.

From the upgrade logs, I can see the following:

```
Investigating (0) cryptsetup-initramfs:amd64 < 2:2.7.0-1ubuntu4 @ii gK Ib >
Broken cryptsetup-initramfs:amd64 Depends on cryptsetup:amd64 < 2:2.7.0-1ubuntu4 @ii pgP > (>= 2:2.7.0-1ubuntu4)
  Considering cryptsetup:amd64 10000 as a solution to cryptsetup-initramfs:amd64 0
  Removing cryptsetup-initramfs:amd64 rather than change cryptsetup:amd64
```

Which I think is the culprit of the problem.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: ubuntu-release-upgrader-core 1:24.04.18
ProcVersionSignature: Ubuntu 6.8.0-31.31-generic 6.8.1
Uname: Linux 6.8.0-31-generic x86_64
NonfreeKernelModules: zfs nvidia_modeset nvidia
ApportVersion: 2.28.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: pass
CrashDB: ubuntu
CurrentDesktop: MATE
Date: Thu May 30 16:37:39 2024
InstallationDate: Installed on 2024-02-25 (95 days ago)
InstallationMedia: Ubuntu-MATE 23.10 "Mantic Minotaur" - Release amd64 (20231010)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: ubuntu-release-upgrader
UpgradeStatus: Upgraded to noble on 2024-05-30 (0 days ago)
VarLogDistupgradeXorgFixuplog:
 INFO:root:/usr/bin/do-release-upgrade running
 INFO:root:No xorg.conf, exiting

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-release-upgrader - 1:24.10.6

---------------
ubuntu-release-upgrader (1:24.10.6) oracular; urgency=medium

  * DistUpgrade: show a message about denied package removals
    (LP: #2073278)
  * data: add cryptsetup-initramfs to removal_denylist.cfg
    (LP: #2067622)
  * Run pre-build.sh: updating mirrors, demotions, and translations.

 -- Nick Rosbrook <email address hidden> Tue, 06 Aug 2024 16:48:41 -0400

[Chris Halse Rogers (raof)]

An upload of ubuntu-release-upgrader to noble-proposed has been rejected from the upload queue for the following reason: "Changing the "The package %s is marked for removal..." string to an f"" string unnecessarily breaks translations, and it looks like the Amharic translation got broken (it retains the old translation, containing a '%s' - I'm not *sure* what python will do when it hits that, but it's not going to be what we want). Otherwise looks fine to me.".