If you're using Gnome Boxes to run virtual machines and you're trying to forward a USB device (like a USB stick or phone), you might have run into this error:
spice-client-glib-usb-helper: Error Failed to drop capabilities: -3
The simple fix:
sudo setcap -r /usr/lib64/spice-gtk/spice-client-glib-usb-acl-helper
Do you have a better fix or a cleaner way to handle this?