I test ubuntu_19.04-xfce-4.14pre2 docker container in xfce-test in VirtualBox. Trash applet/plugin does not work. There is an icon on the panel but it is generic. Clicking the icon gives an error dialog with: Failed to connect to the Trash. GDbus.Error:org... Operation not supported
Thanks for reporting ! Meh, looks like that's my fault ... I removed "xfce4-panel" compiled from source from my system at some point and used the packagers version. Resulting in no support for the "Trash Panel Applet" during thunar build Since I was the one building the release "Thunar-1.8.7.tar.bz2", it is probably missing in the archive. Next release I promise to more carefully check all opt-ins for the build :[