Package: x2godesktopsharing

Version:  3.2.0.0-0~283~ubuntu18.04.1

So I installed X2Go with x2godesktopsharing inside some docker container. If I would share a remote desktop session, it could not be found by the client.

I found out that x2golistdesktop calls "ss". This was not installed. There was no error and it failed silently.

The ubuntu package iproute2 contains the ss command. I suggest you add this to the dependencies.