Ubuntu
livecd-rootfs package

livecd-rootfs incorrectly installs core snap as implicit dep of other base snaps

Bug #1957123 reported by Steve Langasek
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
livecd-rootfs (Ubuntu)
Fix Released
High
Steve Langasek
Focal
Fix Released
High
Steve Langasek

Bug Description

[Justification]
The focal and jammy desktop images include a gtk-common-themes snap which uses base: bare. This is obviously supposed to mean the snap has no external dependencies on a particular core snap. Unfortunately, the logic in livecd-rootfs is broken, and when processing the bare snap itself, seeing that it has no base: declared in its own metadata, interprets this as meaning there is an implicit dependency on the core snap and pulls in a whole separate root filesystem pointlessly.

We should:
- fix livecd-rootfs to not look for base snaps of snaps which are themselves type: base
- make it a fatal build error for focal an later to try to build an image that pulls in the core snap, since this is legacy (the Ubuntu 16.04 rootfs should not be used in Ubuntu 20.04 and later images) and it's a bad bug if it does get pulled in.

[Test case]
All daily images should build successfully for all flavors with the updated livecd-rootfs. If this change introduces any build failures, it should be reverted until the underlying problem (seeding a snap that requires 'core' as a base) can be resolved.

See original description

Related branches

livecd-rootfs:no-base-snaps-for-base-snaps
William Wilson: Pending requested
Diff: 47 lines (+23/-4)
2 files modified
debian/changelog (+11/-0)
live-build/functions (+12/-4)
Steve Langasek (vorlon)
description: updated
Steve Langasek (vorlon)
Changed in livecd-rootfs (Ubuntu):
importance: Undecided → High
Changed in livecd-rootfs (Ubuntu Focal):
importance: Undecided → High
Changed in livecd-rootfs (Ubuntu):
assignee: nobody → Steve Langasek (vorlon)
Changed in livecd-rootfs (Ubuntu Focal):
assignee: nobody → Steve Langasek (vorlon)
Changed in livecd-rootfs (Ubuntu):
status: New → Fix Committed
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package livecd-rootfs - 2.751

---------------
livecd-rootfs (2.751) jammy; urgency=medium

  * Revert patch for unmounting in local builds as it is causing autopkgtest
    regressions

 -- William 'jawn-smith' Wilson <email address hidden> Wed, 12 Jan 2022 13:43:24 -0600

Changed in livecd-rootfs (Ubuntu):
status: Fix Committed → Fix Released
Revision history for this message
Timo Aaltonen (tjaalton) wrote : Please test proposed package

Hello Steve, or anyone else affected,

Accepted livecd-rootfs into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/livecd-rootfs/2.664.37 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, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. 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.

Changed in livecd-rootfs (Ubuntu Focal):
status: New → Fix Committed
tags: added: verification-needed verification-needed-focal
Revision history for this message
Steve Langasek (vorlon) wrote :

The daily images for focal use livecd-rootfs from -proposed by default when building, and they have built successfully. Today's Ubuntu focal daily-live image no longer has the core snap included. All flavors have successful builds within the past 2 days. Verified.

tags: added: verification-done verification-done-focal
removed: verification-needed verification-needed-focal
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package livecd-rootfs - 2.664.37

---------------
livecd-rootfs (2.664.37) focal; urgency=medium

  * Do not look for a base snap on snaps of type base, because recursive
    dependencies are not allowed for snaps. LP: #1957123.
  * Treat it as a fatal error if we are asked to install a snap that would
    pull in the core snap. Ubuntu 20.04 and Ubuntu 22.04 official images
    should never require snaps that depend on an Ubuntu 16.04 runtime, this
    indicates a misconfiguration that will bloat the install.

 -- Steve Langasek <email address hidden> Tue, 18 Jan 2022 16:16:18 -0800

Changed in livecd-rootfs (Ubuntu Focal):
status: Fix Committed → Fix Released
Revision history for this message
Brian Murray (brian-murray) wrote : Update Released

The verification of the Stable Release Update for livecd-rootfs has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

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