Slow icon loading / blank app grid icons on login after upgrading to Fedora Silverblue 45 beta

Description

After performing a major version upgrade from Fedora Silverblue 44 to Fedora Silverblue 45, the GNOME Shell App Grid exhibits a noticeable delay when loading application icons upon every fresh boot or reboot.

When entering the App Grid immediately after logging in, all application placeholders appear as blank/grayed-out squares. The actual application icons take roughly 5–10 seconds to populate sequentially.

Environment Details

  • OS: Fedora Silverblue 45 (OSTree)

  • Desktop Environment: GNOME Shell (Wayland session)

  • Upgrade Path: Fedora Silverblue 44 $\rightarrow$ Fedora Silverblue 45

Steps to Reproduce

  1. Upgrade Fedora Silverblue 44 to 45 via rpm-ostree rebase.

  2. Reboot into the Fedora 45 deployment and log into the user session.

  3. Open the App Grid (Super key or clicking “Show Apps”) immediately after startup.

Observed Behavior

  • Application icons are blank or delayed, rendering sequentially over several seconds instead of appearing instantly.

  • Flatpak exports seem to trigger fallback disk lookups rather than reading from a pre-compiled icon cache.

Expected Behavior

  • Application icons should render instantly from the binary icon cache upon opening the App Grid.

Troubleshooting / Workaround Performed

Running the following commands to regenerate the system Flatpak icon cache and purge user shell caches does not resolves the issue:

Bash

# Rebuild Flatpak icon cache
sudo gtk-update-icon-cache -f /var/lib/flatpak/exports/share/icons/hicolor/

# Clear stale GNOME Shell cache
rm -rf ~/.cache/gnome-shell/ ~/.cache/gnome-software/

$ journalctl --user -f /usr/bin/gnome-shell
Aug 25 20:22:58 fedora gnome-shell[6944]: Obtained a high priority EGL context
Aug 25 20:22:58 fedora gnome-shell[6944]: Using public X11 display :0, (using unix:/tmp/.X11-unix/X1 for managed services)
Aug 25 20:22:58 fedora gnome-shell[6944]: Using Wayland display name 'wayland-0'
Aug 25 20:22:58 fedora gnome-shell[6944]: Unset XDG_SESSION_ID, getCurrentSessionProxy() called outside a user session. Asking logind directly.
Aug 25 20:22:58 fedora gnome-shell[6944]: Registering session with GDM
Aug 25 20:22:58 fedora gnome-shell[6944]: Will monitor session 2
Aug 25 20:22:58 fedora gnome-shell[6944]: Error looking up permission: GDBus.Error:org.freedesktop.portal.Error.NotFound: No entry for geolocation
Aug 25 20:23:00 fedora gnome-shell[6944]: GNOME Shell started at Tue Aug 25 2026 20:22:58 GMT+0530 (India Standard Time)
Aug 25 20:23:00 fedora gnome-shell[6944]: Registering display with GDM
Aug 25 20:23:24 fedora gnome-shell[6944]: Could not create bluez object manager: Timeout was reached
$ journalctl --user -b 0 | grep -Ei "glycin|bwrap|librsvg|icon|pixbuf" | tail -n 30
Aug 25 20:22:59 fedora gnome-software[7281]: gs_icon_downloader_update_priority: assertion 'GS_IS_ICON_DOWNLOADER (self)' failed
Aug 25 20:23:12 fedora org.mozilla.firefox.desktop[9667]: [Parent 2, Main Thread] WARNING: Could not load a pixbuf from icon theme.
Aug 25 20:23:12 fedora org.mozilla.firefox.desktop[9667]: This may indicate that pixbuf loaders or the mime database could not be found.: 'glib warning', file checkouts/gecko/toolkit/xre/nsSigHandlers.cpp:200
Aug 25 20:23:12 fedora firefox-bin[9667]: Could not load a pixbuf from icon theme.
                                          This may indicate that pixbuf loaders or the mime database could not be found.

i rebased to 44

Please be aware that the Fedora 45 beta hasn’t been released yet and right now is still undergoing active development.

However, this is a known issue and a fix has been merged into the code which I suspect might be released in the Gnome RC. See here for more details: https://gitlab.gnome.org/GNOME/glycin/-/work_items/315

The recent gnome-shell merge probably wont fix the issue until they lower the 25 value

26 is the date of beta release so it has already been in beta freeze state which considered as beta
yes i think it was that bug as you have given a reference of

The beta freeze may have already happened but the beta won’t be released until 15th September, assuming there aren’t any blockers).

This issue is caused by long standing problems with a single shared and limited thread pool in gio

Properly using the libglycin async API would fix it. But since multiple apps and libraries are affected, there is a workaround in libglycin 2.2.beta.1 which solves the issue

https://download.gnome.org/sources/glycin/2.2/glycin-2.2.beta.1.news