discover home never loads

[Lyn Perrine]

To reproduce run plasma-discover and see the home tab and see it never finish loading. I can switch to other packages categories fine thought just the home tab is broken. I expected a home tab to load here.

Description: Ubuntu Lunar Lobster (development branch)
Release: 23.04

plasma-discover:
  Installed: 5.27.2-0ubuntu1
  Candidate: 5.27.2-0ubuntu1
  Version table:

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: plasma-discover 5.27.2-0ubuntu1
ProcVersionSignature: Ubuntu 5.19.0-28.29-generic 5.19.17
Uname: Linux 5.19.0-28-generic x86_64
ApportVersion: 2.26.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: LXQt
Date: Wed Mar 1 18:36:09 2023
InstallationDate: Installed on 2020-02-05 (1120 days ago)
InstallationMedia: Lubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20191226)
SourcePackage: plasma-discover
UpgradeStatus: Upgraded to lunar on 2023-01-07 (53 days ago)

[Launchpad Janitor (janitor)]

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

[Chris Guiver (guiverc)]

I just tried this on my primary box; same reaction (home screen never shows on plasma discover).

guiverc@d7050-next:~$ plasma-discover
org.kde.plasma.libdiscover: Couldn't find the backend: "kns-backend" among ("fwupd-backend", "kns-backend", "packagekit-backend", "snap-backend")
fetch ratings! true
adding empty sources model QStandardItemModel(0x559d39cfee80)
kf.kirigami: Failed to find a Kirigami platform plugin
qrc:/qml/Feedback.qml:2:1: module "org.kde.userfeedback" is not installed
no component found for "com.ubuntu.ubuntu"
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/kirigami.2/ScrollablePage.qml:200:9: QML MouseArea: Binding loop detected for property "implicitHeight"
file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/kirigami.2/ScrollablePage.qml:200:9: QML MouseArea: Binding loop detected for property "implicitHeight"
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
took really long to fetch PackageKitBackend(0x559d39ce2400)
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12871")
PackageKit stopped running!

I exited, restart & same effect..
I can use other 'tabs' in the program, just returning to HOME has "Loading..." and four 'bars' that move...

(second load attempt follows & messages from qterminal)

guiverc@d7050-next:~$ plasma-discover
org.kde.plasma.libdiscover: Couldn't find the backend: "kns-backend" among ("fwupd-backend", "kns-backend", "packagekit-backend", "snap-backend")
fetch ratings! false
adding empty sources model QStandardItemModel(0x5577824aad80)
kf.kirigami: Failed to find a Kirigami platform plugin
qrc:/qml/Feedback.qml:2:1: module "org.kde.userfeedback" is not installed
no component found for "com.ubuntu.ubuntu"
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12922")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12922")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12922")
Qt Quick Layouts: Detected recursive rearrange. Aborting after two iterations.
Qt Quick Layouts: Detected recursive rearrange. Aborting after two iterations.
couldn't find ("org.kde.kio") which is supposedly extended by "org.kde.kio.admin"
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12922")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.12922")
org.kde.plasma.libdiscover: cannot infer categories from CategoryFilter::AppstreamIdWildcardFilter
packagekitqt.transaction: Unknown Transaction prop...

[Chris Guiver (guiverc)]

As response to comment on #lubuntu-devel by Rik Mills

<lubot> [telegram] <RikMills> cant you try reinstalling the previous version? (re @lynorian: https://bugs.launchpad.net/ubuntu/+source/plasma-discover/+bug/2008968 filed a bug about it)
<lubot> [telegram] <RikMills> i.e. the 5.27.1 debs from: https://launchpad.net/ubuntu/+source/plasma-discover/5.27.1-0ubuntu1/+build/25621275

guiverc@d7050-next:~$ wget https://launchpad.net/ubuntu/+source/plasma-discover/5.27.1-0ubuntu1/+build/25621275/+files/plasma-discover_5.27.1-0ubuntu1_amd64.deb

guiverc@d7050-next:~$ wget https://launchpad.net/ubuntu/+source/plasma-discover/5.27.1-0ubuntu1/+build/25621275/+files/plasma-discover-common_5.27.1-0ubuntu1_all.deb

guiverc@d7050-next:~$ sudo apt install ./plasma-discover_5.27.1-0ubuntu1_amd64.deb ./plasma-discover-common_5.27.1-0ubuntu1_all.deb
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'plasma-discover' instead of './plasma-discover_5.27.1-0ubuntu1_amd64.deb'
Note, selecting 'plasma-discover-common' instead of './plasma-discover-common_5.27.1-0ubuntu1_all.deb'
The following package was automatically installed and is no longer required:
[snip]

and on executing `plamsma-discover` now I get expected operation.
(only a brief display of loading before packages are listed in home screen)

guiverc@d7050-next:/de2900/lubuntu_64$ apt-cache policy plasma-discover
plasma-discover:
  Installed: 5.27.1-0ubuntu1
  Candidate: 5.27.2-0ubuntu1
  Version table:
     5.27.2-0ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu lunar/universe amd64 Packages
 *** 5.27.1-0ubuntu1 100
        100 /var/lib/dpkg/status

  libsnapd-qt-2-1
Use 'sudo apt autoremove' to remove it.
...

[Rik Mills (rikmills)]

git bisecting between plasma-discover v5.27.1 and v5.27.2 seems to indicate that the 1st bad commit with this issue is:

https://invent.kde.org/plasma/discover/-/commit/5dadd14ff12b8a6afae2c557d5948c5c66e1898c

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
https://iso.qa.ubuntu.com/qatracker/reports/bugs/2008968

[Thomas Ward (teward)]

Tested KDE Plasma environment on Debian Unstable in a VM. I am UNABLE to replicate this issue in Debian Unstable with the current version of Discover in there.

This might be an Ubuntu/Kubuntu/Lubuntu specific issue.

[Rik Mills (rikmills)]

SUMMARY

In Kubuntu and Lubuntu/UbuntuStudio 23.04 (which both ship discover), 5.27.2 discover 'home' tab never loads at startup, or when re-selected after viewing another tab.

Additionally, while discover is both the foreground application and the home tab is active, discover process uses a high cpu load. Selecting another tab or another app as foreground cuts off the usage.

Downstream bug: https://bugs.launchpad.net/ubuntu/+source/plasma-discover/+bug/2008968

STEPS TO REPRODUCE
1. Run the daily live 23.04 ISO from http://cdimage.ubuntu.com/kubuntu/daily-live/current/ and start discover; or
2. Install discover 5.27.2 on 22.10 via ppa:kubuntu-ppa/backports

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.27.2
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Packagekit: 1.2.6-3 (direct sync from debian testing/unstable)

ADDITIONAL INFORMATION

Appears to be a regression introduced by commit https://invent.kde.org/plasma/discover/-/commit/5dadd14ff12b8a6afae2c557d5948c5c66e1898c

This was confirmed by git bisect of the changes in 5.27.2 since 5.27.1, and confirmed by test adding a patch reverting that commit to our packaging.

Konsole output after several launches:

lunar@lunar:~$ plasma-discover
fetch ratings! false
adding empty sources model QStandardItemModel(0x56409f738490)
no component found for "com.ubuntu.ubuntu"
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.94")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.94")
packagekitqt.transaction: Unknown Transaction property: "Sender" QVariant(QString, ":1.94")

which does not differ from 5.27.1 or the reverted state as far as I can see. Though there is some variation on output from testers.

[Aleix Pol (aleixpol-kde)]

https://invent.kde.org/plasma/discover/-/merge_requests/498

[Rik Mills (rikmills)]

Upstream MR seems to fix the issue: https://invent.kde.org/plasma/discover/-/merge_requests/498

[Rik Mills (rikmills)]

(In reply to Aleix Pol from comment #1)
> https://invent.kde.org/plasma/discover/-/merge_requests/498

Applied to a test build. Appears to fix the issue, so thanks!

[Aleix Pol (aleixpol-kde)]

Git commit a5fb09b82833437ef3aed72b4d987c9906f3ec27 by Aleix Pol i Gonzalez.
Committed on 03/03/2023 at 15:42.
Pushed by apol into branch 'master'.

pk: Don't forget to finish streams

The stream would remain open ad eternum, hoping for a finish() call that
would never come.

M +3 -1 libdiscover/backends/PackageKitBackend/PackageKitBackend.cpp

https://invent.kde.org/plasma/discover/commit/a5fb09b82833437ef3aed72b4d987c9906f3ec27

[Aleix Pol (aleixpol-kde)]

Git commit 29ba6422a0321ed9ccef7abe3a0a47a688b936f4 by Aleix Pol Gonzalez, on behalf of Aleix Pol i Gonzalez.
Committed on 03/03/2023 at 16:50.
Pushed by apol into branch 'Plasma/5.27'.

pk: Don't forget to finish streams

The stream would remain open ad eternum, hoping for a finish() call that
would never come.

(cherry picked from commit a5fb09b82833437ef3aed72b4d987c9906f3ec27)

M +3 -1 libdiscover/backends/PackageKitBackend/PackageKitBackend.cpp

https://invent.kde.org/plasma/discover/commit/29ba6422a0321ed9ccef7abe3a0a47a688b936f4

[Launchpad Janitor (janitor)]

This bug was fixed in the package plasma-discover - 5.27.2-0ubuntu2

---------------
plasma-discover (5.27.2-0ubuntu2) lunar; urgency=medium

  * Add upstream_fix-LP2008968.patch to fix loading of Discover's 'home'
    tab. (LP: #2008968).

 -- Rik Mills <email address hidden> Fri, 03 Mar 2023 16:50:36 +0000

[Paul Worrall (nicknak)]

*** Bug 466865 has been marked as a duplicate of this bug. ***

[Watisthispoo (watisthispoo)]

*** Bug 467063 has been marked as a duplicate of this bug. ***