To debug, as posted by @qlrd, run the program with `RUST_LOG="debug"` or single out the clipboard with `RUST_LOG="info,egui_winit::clipboard=debug"`.
Had some results with `WAYLAND_DEBUG=1 RUST_LOG="info,egui_winit::clipboard=debug" gossip |& grep data`, but unable to interpret them according https://gitlab.gnome.org/GNOME/mutter/-/issues/1250