The Hyprland flake pins its own older nixpkgs (Qt 6.11.1) and builds xdg-desktop-portal-hyprland with it. Qt style plugins (qt6ct, kvantum) installed from the system nixpkgs are built against Qt 6.11.2, so loading them into the portal's hyprland-share-picker segfaults it. The picker dies before showing its window, gpu-screen-recorder sees the portal request cancelled, and Noctalia recordings never produce a file. Drop the overlay override so the system nixpkgs portal package (same source rev, linked against Qt 6.11.2) is used instead.