Icons in headerbar not loading

[engstk]

Description
Since v3.0.5, icons in headerbar not load and it shows a generic in it's place.
Happens with dark and light mode, no matter the theme.
Source built with official MS .NET SDK for Debian

To Reproduce
First open logs, Debian 13.3:
`(dotnet:3636): Gtk-WARNING **: 20:52:10.838: Failed to load icon /usr/share/icons/hicolor/scalable/actions/tool-move-cursor-symbolic.svg: Unrecognized image file format

(dotnet:3636): Gtk-WARNING **: 20:52:10.922: Failed to load icon /usr/share/icons/hicolor/scalable/actions/tool-antialiasing-enabled-symbolic.svg: Unrecognized image file format

(dotnet:3636): Gtk-WARNING **: 20:52:10.925: Failed to load icon /usr/share/icons/hicolor/scalable/actions/adjustments-brightnesscontrast-symbolic.svg: Unrecognized image file format

(dotnet:3636): Gtk-WARNING **: 20:52:10.925: Failed to load icon /usr/share/icons/hicolor/scalable/actions/effects-default-symbolic.svg: Unrecognized image file format`

Additional Info
Seems like introduces the issue cae27b2
Reverting the changes fixes it. All the icons on that change are not rendered correctly.

Currently:

Fixed:

Version
Since v3.0.5

[cameronwhite]

Source built with official MS .NET SDK for Debian

If you're building from source, could you let me know which GTK version you have on your system? From what I recall those icon changes were trying to work around changes to how GTK loads SVGs in more recent versions

[engstk]

This is on xfce 4.20 in Debian 13.3.
libgtk-4 is 4.18.6

[cameronwhite]

Thanks, I was able to reproduce with the snap package (the flatpak package seems okay)

[rolandixor]

Can confirm this as well - happening with the Snap, but not the Flatpak

[cameronwhite]

On my Mac I recently noticed similar icon issues resurfacing again (pretty sure this was from the GTK 4.22 upgrade).
It seems like our icons are in a good state for GTK 4.20, but both 4.18 and 4.22 have issues