"Restore default configuration" can restore Virginia/Jammy repositories on an upgraded Mint 22.3 Zena system

Summary

On a Linux Mint 22.3 Zena system, Software Sources restored the default repositories as Linux Mint 21.3 Virginia / Ubuntu 22.04 Jammy.

The system had been upgraded to Mint 22.3 and was otherwise running predominantly Zena/Noble packages. However, an old base-files package (21.3.0) was still installed.

This produced an inconsistent system identity:

/etc/linuxmint/info:

RELEASE=22.3
CODENAME=zena
DESCRIPTION="Linux Mint 22.3 Zena"

while /etc/os-release reported:

VERSION="21.3 (Virginia)"
VERSION_CODENAME=virginia
UBUNTU_CODENAME=jammy

Software Sources consequently displayed:

Main (virginia)
Base (jammy)

Using Restore the default configuration generated an official-package-repositories.list containing Virginia/Jammy repositories, without warning that /etc/linuxmint/info identified the installed release as Zena.

Result

Subsequent APT operations started replacing some Zena/Noble packages with Virginia/Jammy packages.

Examples recorded in APT history include:

chromium:
152.0.7977.64~linuxmint1+zena
  -> 152.0.7977.82~linuxmint1+virginia

and NVIDIA packages such as:

libnvidia-common-580:
580.173.02-0ubuntu0.24.04.1
  -> 580.178.04-0ubuntu0.22.04.1

Other Jammy packages were also introduced into the otherwise Noble-based system.

The problem eventually became visible when Docker installed pigz 2.6 from Jammy while the system already had zlib 1.3 from Noble. unpigz then failed with:

pigz: abort: zlib version less than 1.2.3

Recovery

The system was recovered by restoring the repositories to:

deb http://packages.linuxmint.com zena main upstream import backport
deb http://archive.ubuntu.com/ubuntu noble main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu noble-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu noble-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ noble-security main restricted universe multiverse

After apt update, a simulated dist-upgrade proposed:

101 upgraded, 0 newly installed, 0 to remove

and correctly replaced the affected Jammy packages with their Noble/Zena counterparts.

The remaining identity inconsistency was traced to:

base-files:
  Installed: 21.3.0
  Zena version: 13ubuntu10mint22.3.0

Installing the Zena package explicitly with --allow-downgrades restored /etc/os-release to:

VERSION="22.3 (Zena)"
VERSION_CODENAME=zena
UBUNTU_CODENAME=noble

The system is now consistent again and Docker works normally with Noble's pigz 2.8.

Suggested safeguard

Before Restore the default configuration rewrites the official repositories, Software Sources could compare the release information from /etc/linuxmint/info with /etc/os-release.

If they disagree (for example Zena vs Virginia), it could either:

1. refuse to restore the repositories until the inconsistency is resolved, or
2. display a prominent warning explaining that the detected system identities do not match.

This would prevent an apparently harmless "restore defaults" operation from configuring repositories belonging to an older Mint/Ubuntu release.

Environment

• Linux Mint 22.3 Zena
• Ubuntu base: Noble 24.04
• Desktop: MATE
• Architecture: amd64
• mintsystem: 8.6.5
• base-files before recovery: 21.3.0
• base-files after recovery: 13ubuntu10mint22.3.0

Start by locating the Software Sources path for “Restore the default configuration” and inspect how it reads /etc/linuxmint/info and /etc/os-release before writing official-package-repositories.list. Reproduce the Zena/Virginia mismatch described in the issue, then verify that the operation refuses to proceed or shows a prominent warning when the identities disagree.