[Bug 1841225] Re: deb to snap transition uses an ubuntu release channel for the core18 snap

[Brian Murray]

Hello Brian, or anyone else affected,

Accepted ubuntu-release-upgrader into disco-proposed. The package will
build now and be available at https://launchpad.net/ubuntu/+source
/ubuntu-release-upgrader/1:19.04.16.7 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.

** Changed in: ubuntu-release-upgrader (Ubuntu Disco)
       Status: In Progress => Fix Committed

** Tags added: verification-needed verification-needed-disco

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to ubuntu-release-upgrader in
Ubuntu.
https://bugs.launchpad.net/bugs/1841225

Title:
  deb to snap transition uses an ubuntu release channel for the core18
  snap

Status in ubuntu-release-upgrader package in Ubuntu:
  Fix Released
Status in ubuntu-release-upgrader source package in Disco:
  Fix Committed
Status in ubuntu-release-upgrader source package in Eoan:
  Fix Released

Bug description:
  [Impact]

  During distro upgrades, additional logic exists that replaces existing
  debs with snaps and refreshes existing, installed snaps to the branch
  of the series we're upgrading to (e.g. from stable/ubuntu-18.04 to
  stable/ubuntu-19.04 etc.). However, the upgrader tries to apply the
  logic for all the snaps it 'supports' in migration, even though snaps
  like core18 do not have per-series branches (and will never have).
  This causes non-fatal failures during installation/refresh of the
  core18 snap on upgrades. Even though this does not cause a crash or
  error, and in theory should should not cause any trouble as core18
  *should* be pulled in as a dependency of the other snaps, it is
  invalid behavior and might result in core18 not being present on the
  end system. Upgrades should not perform commands that fail, if
  possible.

  [Test Case]

  * Prepare a bionic machine
  * Make sure ubuntu-desktop and snapd are installed on it
  * Make sure core18 is *not* installed on the system - if there are any snaps installed, remove them
  * Perform an upgrade to disco (with the --proposed option, to use disco-proposed)
  * Reboot
  * Make sure that the upgrade succeeded
  * Check if core18 is installed, open /var/log/dist-upgrade/main.log and look for 'install of snap core18', make sure the command succeeded

  [Regression Potential]

  The changes have been constrained to the DistUpgradeQuirks place, only
  to the snap handling pieces. So any possible regressions should be
  visible in the snap replacement/refresh areas. Most probable ones
  would be for the snaps not being installed/refreshed properly, or
  using the wrong channels/branches.

  [Original Description]

  The release upgrader (DistUpgradeQuirks.py) tries to run the following
  command when upgrading a system without snaps installed to Ubuntu
  19.10 (eoan):

  snap install --channel stable/ubuntu-19.10 core18

  This channel does not exist and the release upgrade will fail e.g.:

  2019-08-23 03:24:45,533 DEBUG quirks: running eoanPostUpgrade
  2019-08-23 03:24:45,533 DEBUG running Quirks.eoanPostUpgrade
  2019-08-23 03:24:51,547 DEBUG install of snap core18 failed
  2019-08-23 03:25:51,348 DEBUG install of snap gnome-3-28-1804 succeeded

  The quirk should be updated so that an ubuntu release channel is not
  used when installing the core18 snap.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1841225/+subscriptions