Missing symbolic icons on newer GTK4 apps from Flathub

[owzim]

• Distribution (version): Ubuntut 22.04 LTS
• Desktop environment: GNOME 42.9
• Installing method: Papirus Installer
• App name (version): Many modern gtk4 GNOME apps, installed from Flathub, in this specific case GNOME Secrets

Some Icons are missing, when using Papirus.

Icons are not missing when using Adwaita.

Obviously the icons are new icons of the Adwaita icons theme. My question is, what is happening here. Is there no fallback mechanism? Do alternative icon themes always have to have an icon with the same name?

• Is it even a Papirus issue?
• Is it a Flatpak issue?
• Is it an Adwaita issue?

Thanks

[morganist]

My question is, what is happening here. Is there no fallback mechanism?

Maybe libadwaita devs have changed some icon names? I've noticed missing icons where they were previously there. We'll look into that.

[owzim]

@morganist is there something more I can provide?

[owzim]

The Yaru Theme (Ubuntu 22.04) has those icons too.

[Asherathe]

My understanding is that Gnome deliberately stopped supporting icon theming.

[owzim]

@Asherathe can you provide any evidence of that being the case?

The fact that Ubuntu's Yaru icon theme is working contradicts that assumption, does it not?

[Raindrac]

Determined to fix this issue for myself, I dug into potential causes, and I've found both a workaround and the surface-level cause of the issue. That issue is that these applications are only loading symbolic icons from icon themes located in /usr/share/icons. If Papirus, or any other icon theme, is installed to a different directory (such as ~/.local/share/icons) then the symbolic icons will break in the affected applications.

I confirmed this by creating a duplicate of the working Adwaita theme and renaming it to Adwaita-Copy. If Adwaita-Copy is installed into ~/.local/share/icons, symbolic icons won't load in the affected applications. This is in spite of how the theme is identical to a working theme, Adwaita.

By installing Papirus directly to /usr/share/icons, the issue went away. If you're running an atomic distribution like me, that directory is read-only; you can work around it by creating an rpm package and layering it with rpm-ostree. If you're using another distro, just move the folder over there normally.

The bug that's causing this is upstream of Papirus, so for now I suggest using this workaround. Someone more experienced with debugging might want to see if they can identify where the issue is located upstream and submit a bug report to the relevant issue tracker.