Created attachment 145510 [details]
Appstream Discover error message

SUMMARY
A bug, presumably related to `rpm-ostree` backend, makes Discover unable to show applications accessible through Appstream.

STEPS TO REPRODUCE
1.  Open Discover
2.  Search for Kate editor

OBSERVED RESULT
An error message stating `Could not open appstream://org.kde.kate.desktop`

EXPECTED RESULT
Kate editor showing up in the applications list

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora Silverblue 35 (Kinoite) 
(available in About System)
KDE Plasma Version: 5.23.4
KDE Frameworks Version: 5.89.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
While it seems the issue is associated with ` OSTree`, another user mentions that this error could also be associated with the fact the Kinoite doesn't ship with ` packagekit`:
`this is most likely due to the fact that we don't ship packagekit on Kinoite.`

We did some troubleshooting to try to understand what's happening, here are the results:

``` 
$ plasma-discover --application appstream://org.kde.kate
$
```
The above command executes successfully (no error message, no shell error exit code), but it shows no output whatsoever

```
$ appstreamcli search kate
Identifier: org.kde.plasma.katesessions [addon]
Name: Kate Sessions
Summary: Kate Session Launcher
Package: kate
Homepage: https://apps.kde.org/kate/
Icon: kate
---
Identifier: org.kde.kate.desktop [desktop-application]
Name: Kate
Summary: Advanced Text Editor
Package: kate
Homepage: https://kate-editor.org/
Icon: org.kde.kate.png
---
Identifier: org.kde.kio_gdrive [addon]
Name: KIO GDrive
Summary: Google Drive integration with KDE Plasma and KDE applications
Package: kio-gdrive
Homepage: https://community.kde.org/KIO_GDrive
Icon: folder-gdrive
---
Identifier: org.gnome.Screenshot.desktop [desktop-application]
Name: GNOME Screenshot
Summary: Save images of your screen or individual windows
Package: gnome-screenshot
Homepage: https://gitlab.gnome.org/GNOME/gnome-screenshot
Icon: org.gnome.Screenshot.png
---
Identifier: xpenguins.desktop [desktop-application]
Name: XPenguins
Summary: Cute little penguins that walk along the tops of your windows
Package: xpenguins
Homepage: http://xpenguins.seul.org/
Icon: xpenguins.png
---
Identifier: org.kde.kwrite.desktop [desktop-application]
Name: KWrite
Summary: Text Editor
Package: kwrite
Homepage: https://kate-editor.org/
Icon: org.kde.kwrite.png
---
Identifier: org.kde.dolphin_plugins [addon]
Name: Dolphin Plugins
Summary: Dolphin integration for revision control systems, Dropbox, and disk images.
Package: dolphin-plugins
Homepage: https://www.kde.org
Icon: system-file-manager
```

```
$ --application appstream://org.kde.kate.desktop
~ ❯ plasma-discover --application appstream://org.kde.kate.desktop
org.kde.plasma.libdiscover: Couldn't find a category for  "fwupd-backend"
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/private/PrivateActionToolButton.qml:74:5: QML Binding: Binding loop detected for property"value"
fwupd: Device not supported: KBG40ZNT512G TOSHIBA MEMORY No releases found: Device KBG40ZNT512G TOSHIBA MEMORY [04e17fcf7d3de91da49a163ffe4907855c3648be] does not currently allow updates: Cannot install update when not on AC power, Device KBG40ZNT512G TOSHIBA MEMORY [04e17fcf7d3de91da49a163ffe4907855c3648be] does not currently allow updates: Cannot install update when not on AC power
kf.newstuff.core: "Error transferring https://distribute.kde.org/khotnewstuff/fonts-providers.xml - server replied: Not Found"
invalid kns backend! "/usr/share/knsrcfiles/kfontinst.knsrc" because: "Invalid Fonts backend, contact your distributor."
org.kde.plasma.libdiscover: Discarding invalid backend "kfontinst.knsrc"
kns error "/usr/share/knsrcfiles/kfontinst.knsrc" "Invalid Fonts backend, contact your distributor."
org.kde.plasma.libdiscover: Couldn't find a category for  "fwupd-backend"
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/GlobalDrawer.qml:354:13: QML ColumnLayout: Binding loop detected for property "height"
qml: error Could not open appstream://org.kde.kate.desktop
```
It launches Discover with the error message I mention at the beginning of this bug report (check attached screenshot)

Thanks,
-Martin