cachyos-hello won't start due to missing SVG support in gdk-pixbuf2-noglycin needed for unity fix

[AM-XR]

Hey everyone, I'm pretty new to Linux and CachyOS, so please forgive me if this issue is based on lack of experience. (For disclosure, i tried to analyse and fix the problem with claue ai)

The Problem: I need both Unity and cachyos-hello to work, but they have conflicting requirements for my case:

• Unity needs: gdk-pixbuf2-noglycin (to fix slow right-click context menus - see this Unity discussion:
  https://discussions.unity.com/t/in-120713-context-menus-open-very-slowly/1690076/32
• cachyos-hello needs: SVG support in gdk-pixbuf, which gdk-pixbuf2-noglycin doesn't have

For the unity fix i removed the default glycin version:

yay gdk-pixbuf2-noglycin
sudo pacman -Rs glycin

The Error: When I try to run cachyos-hello, it crashes immediately:

thread 'main' panicked at src/window.rs:54:53: called \Result::unwrap()` on an `Err` 
value: Error { domain: gdk-pixbuf-error-quark, code: 3, message: 
"Couldn't recognize the image file format for file 
"/usr/share/icons/hicolor/scalable/apps//org.cachyos.hello.svg"" }`

This issue does not come up with any other program yet.

Path Issue:

• Wrong path (what cachyos-hello is looking for):
  /usr/share/icons/hicolor/scalable/apps//org.cachyos.hello.svg (note the double slash)

• Correct path (where the file actually exists):
  /usr/share/icons/hicolor/scalable/apps/org.cachyos.hello.svg

What I've discovered:

• The official gdk-pixbuf2 package includes SVG support (via librsvg)
• gdk-pixbuf2-noglycin only has 3 loaders: wmf, openraw, and webp - no SVG
• When I check gdk-pixbuf-query-loaders | grep svg, it returns nothing
• The SVG icon file exists at /usr/share/icons/hicolor/scalable/apps/org.cachyos.hello.svg

What I've tried:

• Reinstalling cachyos-hello - didn't help
• Clearing icon caches - didn't help
• Installing/reinstalling librsvg - didn't help (loader still not registered)

Possible underlying issue and possible feature request

(Disclosure: Developed with claude ai)
Current Issue: cachyos-hello uses gdk_pixbuf::Pixbuf::from_file() to directly load SVG icons, which requires an SVG loader in gdk-pixbuf. This fails when using gdk-pixbuf2-noglycin (which lacks SVG support).

How Other Programs Handle SVG Icons Successfully:

1. Icon Theme API (Recommended):
   • Use GTK's icon theme system: gtk::IconTheme::load_icon()
   • Request icon by name (e.g., "org.cachyos.hello") instead of hardcoded path
   • GTK handles rendering internally, doesn't depend on gdk-pixbuf loaders
   • Works across different gdk-pixbuf variants
2. Alternative Renderers:
   • Use librsvg directly via rsvg::Loader
   • Use Cairo for SVG rendering
   • Qt apps use their own libqsvg (doesn't depend on gdk-pixbuf)

Feature Request: Replace the direct file loading at src/window.rs:54:53 with GTK's icon theme API to improve compatibility with different gdk-pixbuf configurations.

Additional System Info

Linux ***** 6.17.9-2-cachyos #1 SMP PREEMPT_DYNAMIC Mon, 24 Nov 2025 17:57:32 +0000 x86_64 GNU/Linux

cachyos-hello 0.19.1-1

KDE Plasma

reeze-darkm Breeze

gdk-pixbuf2-noglycin 2.44.4-2

[AM-XR]

Found a solution: Had to install a librsvg version that supports noglycin to get the needed SVG support back. So seems to be a newbie user error :)

aur/librsvg-noglycin 2.61.3-1 (+6 2.91) 
    SVG rendering library, compatible with gdk-pixbuf2-noglycin

# Install librsvg-noglycin (replaces regular librsvg)
yay -S librsvg-noglycin

# It will probably ask to replace librsvg - say YES

# Update the loaders cache
sudo gdk-pixbuf-query-loaders --update-cache

# Check if SVG loader is now present
gdk-pixbuf-query-loaders | grep svg

# Try cachyos-hello
cachyos-hello