GTK-based Flatpak apps freeze on workspace switch in Hyprland (Wayland)

[revanthlol]

Description

When running GTK-based Flatpak apps (Spider Web, Karere) on Arch Linux with Hyprland, the apps freeze after switching workspaces. The only way to recover temporarily is to click the maximize button.

This seems related to Wayland/X11 backend issues and accessibility socket (AT-SPI) registration.

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Steps to Reproduce

1. Install Spider Web or Karere via Flatpak.
2. Run the app (flatpak run io.github.zaedus.spider or flatpak run io.github.karere.Karere).
3. Switch to another workspace and return to the app.
4. Observe that the app is frozen/unresponsive.
5. Clicking maximize restores interactivity temporarily.

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Observed Behavior

• Freezes on workspace switch.

• AT-SPI / GTK warnings in the terminal:

  Gtk-WARNING **: Error embedding AT-SPI socket: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner
  Gtk-WARNING **: Failed to open display
  

• Mesa Vulkan warnings (Intel GPU):

  MESA-INTEL: warning: support YUV colorspace with DRM format modifiers
  MESA-INTEL: warning: support more multi-planar formats with DRM modifiers
  

• Attempts to force X11 (GDK_BACKEND=x11) fail unless the Flatpak has fallback-x11 socket.

• Flatpak overrides for Wayland/X11/pulseaudio/session-bus don’t fix freezes.

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Environment

• OS: Arch Linux (latest)

• Compositor: Hyprland (Wayland)

• GPU/Driver: Intel, Mesa (vulkan support)

• Flatpak apps tested:

  • Spider Web (io.github.zaedus.spider)
  • Karere (io.github.karere.Karere)

• Flatpak runtime: Freedesktop / GNOME (tried both)

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Workarounds Tried

1. Force X11 backend and fallback socket:

   flatpak override --user --env=GDK_BACKEND=x11 io.github.zaedus.spider
   flatpak override --user --socket=fallback-x11 io.github.zaedus.spider

2. Force Wayland backend:

   flatpak override --user --env=GDK_BACKEND=wayland io.github.zaedus.spider
   flatpak override --user --socket=wayland io.github.zaedus.spider

3. Reinstall at-spi2-core (accessibility):

   sudo pacman -S at-spi2-core

4. Tried both Freedesktop and GNOME runtimes in Flatpak.

5. Setting NO_AT_BRIDGE=1 environment variable (AT-SPI disable) — not yet tested fully.

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Possible Cause

• GTK apps expect certain GNOME/Mutter signals on workspace focus, which Hyprland does not provide.
• Accessibility socket (AT-SPI) fails to register in non-GNOME desktops.
• Flatpak sandboxing may interfere with X11/Wayland communication.

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Logs & Errors

Example GTK warnings

Gtk-WARNING **: Error embedding AT-SPI socket: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner
Gtk-WARNING **: Failed to open display

Mesa Intel Vulkan warnings

MESA-INTEL: warning: support YUV colorspace with DRM format modifiers
MESA-INTEL: warning: support more multi-planar formats with DRM modifiers

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Additional Notes

• Works fine in GNOME or X11-based environments.
• Freezing is consistent across multiple Flatpak GTK apps.
• Likely a Wayland + GTK + Hyprland + Flatpak interaction issue.