Kubuntu 16.04.1 discover empty after fresh install

[Damien]

[Impact]

 * A previous update made AppStream use modern-style component-ids, thereby breaking the Qt library if it is reading data from the cache and if that data happens to be a desktop-application.
 * This leads to KDE's Discover not displaying applications.
 * The issue was introduced by a patch to the Xenial version of AppStream, and is not present in any other version of the package in Ubuntu, affecting Xenial only.

[Test Case 1]

 * Update the libappstream-qt package, run Discover: All apps should be loaded correctly.

[Regression Potential]

 * Low, this change affects only the Qt bindings and nothing else. The change is also a simple string value change.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jochen S. (jochen8)]

Maybe related to https://bugs.launchpad.net/ubuntu/+source/plasma-discover/+bug/1577918 ?

[Alberto Salvia Novella (es20490446e)]

Please:

1. Install the "muon" package.
2. If that fixes the problem, mark this report as duplicate of bug #1577918.
3. If it doesn't, in bug #1577918, say this report isn't a duplicate.
4. In this report, for the "packagekit" package, set status back to "confirmed".

Thank you.

[Damien (damien.kde)]

Please read the bug description. I installed muon and that did not solve the problem.
Related bug: https://bugs.kde.org/show_bug.cgi?id=376241 (note that this affects many users).

[Carlo Vanini (silhusk)]

All packages are marked as "technical" and therefore are hidden from the list in Discover. That's because libAppstreamQt looks for type "desktop" where instead it is "desktop-application" in the metadata.

[Matthias Klumpp (ximion)]

I just wanted to reject that assumption because the version of AppStream in Xenial was too old, but it turns out you're right: A backport from a newer version broke this, and I didn't notice because my AppStreamQt is also newer (and using a better architecture where this bug can't happen anymore).
So, +1 on the patch. I would probably when we are patching this, also add a few minor fixes to the autopkgtests in Xenial (I might do that tomorrow).

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "change type string from "desktop" to "desktop-application"" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Matthias Klumpp (ximion)]

Added a version of this patch which also fixes the automatic tests.

[Brian Murray (brian-murray)]

Does this not need fixing in Zesty? If that is the case please explain why not in the bug description.

[Matthias Klumpp (ximion)]

I added an explanation (basically, a previous bugfix fixing GNOME Software broke this for the Qt bindings).

[Brian Murray (brian-murray)]

Hello Damien, or anyone else affected,

Accepted appstream into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/appstream/0.9.4-1ubuntu3 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 to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

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

[Anonymous (cicerone55)]

Tested Xenial (0.9.4-1ubuntu3), didn't work.

[Matthias Klumpp (ximion)]

@cicerone55: Are you sure you updated the right package? Please check if libappstreamqt1 is at that particular version, because that's where the bug is located.

[Carlo Vanini (silhusk)]

It works for me updating libappstreamqt1 to 0.9.4-1ubuntu3 on Xenial 16.04.2.

Can someone else confirm, please?

[Mario Badr (mariobadr)]

Muon did not work.

sudo apt install libappstreamqt1/xenial-proposed did work after following the EnableProposed on Xenial 16.04.2.

Thanks!

[Matthias Klumpp (ximion)]

Okay, 3:1 for the "the update works" camp, as it looks like ;-)

[Anonymous (cicerone55)]

I don't recall what I did last time but now I installed it again and it works.

[Robie Basak (racb)]

So it looks like this was a regression caused by the fix for bug 1644498 landing in Xenial?

[Launchpad Janitor (janitor)]

This bug was fixed in the package appstream - 0.9.4-1ubuntu3

---------------
appstream (0.9.4-1ubuntu3) xenial; urgency=medium

  [ Carlo Vanini ]
  * modern-metadata-in-qt.patch: Fix type label for desktop
    applications in the Qt library. (LP: #1663695)

  [ Matthias Klumpp ]
  * Fix autopkgtest tests.

 -- Matthias Klumpp <email address hidden> Fri, 31 Mar 2017 13:21:01 +0100

[Robie Basak (racb)]

The verification of the Stable Release Update for appstream has completed successfully and the package has now been 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.