Have you tried qemu and gnome-boxes?
Yes, this is what I get:
tc@box:~$ gnome-boxes
gnome-boxes: /usr/local/lib/libosinfo-1.0.so.0: version `LIBOSINFO_1.4.0' not found (required by gnome-boxes)
gnome-boxes: /usr/local/lib/libosinfo-1.0.so.0: version `LIBOSINFO_1.7.0' not found (required by gnome-boxes)
gnome-boxes: /usr/local/lib/libosinfo-1.0.so.0: version `LIBOSINFO_1.3.0' not found (required by gnome-boxes)
gnome-boxes: /usr/local/lib/libvirt-gobject-1.0.so.0: version `LIBVIRT_GOBJECT_3.0.0' not found (required by gnome-boxes)
gnome-boxes: /usr/local/lib/libvirt-gconfig-1.0.so.0: version `LIBVIRT_GCONFIG_3.0.0' not found (required by gnome-boxes)
gnome-boxes: /usr/local/lib/libvirt-gconfig-1.0.so.0: version `LIBVIRT_GCONFIG_0.2.4' not found (required by gnome-boxes)
gnome-boxes: /usr/local/lib/libvirt-gconfig-1.0.so.0: version `LIBVIRT_GCONFIG_2.0.0' not found (required by gnome-boxes)
Please note: libosinfo.tcz, libosinfo-gir.tcz, libosinfo-dev.tcz are all installed and so is libvirt-glib.tcz (providing libvirt-gobject and libvirt-gconfig).
However, IMHO it would be better to have Virtualbox working on TC, because it has its own engine and must not rely on an external emulator; moreover, qemu in TC is a bit outdated (repo version is 3.1.0, current version is 5.0.0).