I think we're good.
So I went ahead, and what follows is the whole history:
############################ root@noc /var/log/apt # sudo apt remove libnx-x11-6:amd64 libx2go-log-perl libx2go-server-db-perl libx2go-server-perl libx2go-utils-perl nx-x11-common nxagent x2goserver x2goserver-common x2goserver-x2goagent x2goserver-xsession libxcompshad3 Reading package lists... Done Building dependency tree Reading state information... Done Package 'x2goserver' is not installed, so not removed Package 'x2goserver-xsession' is not installed, so not removed The following packages were automatically installed and are no longer required: libcapture-tiny-perl libconfig-simple-perl libdbd-pg-perl libdbd-sqlite3-perl libdbi-perl libfile-which-perl libpq5 libswitch-perl libxcomp3 lsof pwgen Use 'sudo apt autoremove' to remove them. The following packages will be REMOVED: libnx-x11-6 libx2go-log-perl libx2go-server-db-perl libx2go-server-perl libx2go-utils-perl libxcompshad3 nx-x11-common nxagent x2goserver-common x2goserver-x2goagent The following held packages will be changed: libx2go-log-perl libx2go-server-db-perl libx2go-server-perl libx2go-utils-perl x2goserver-common x2goserver-x2goagent 0 upgraded, 0 newly installed, 10 to remove and 25 not upgraded. 2 not fully installed or removed. After this operation, 7,260 kB disk space will be freed. Do you want to continue? [Y/n] y (Reading database ... 162568 files and directories currently installed.) Removing libx2go-server-perl (4.1.0.3-5) ... Removing libx2go-server-db-perl (4.1.0.4-0~1975~ubuntu20.04.1) ... Removing libx2go-log-perl (4.1.0.4-0~1975~ubuntu20.04.1) ... Removing x2goserver-x2goagent (4.1.0.3-5) ... Removing nxagent (2:3.5.99.23-1build1) ... Removing libxcompshad3:amd64 (2:3.5.99.23-1build1) ... Removing libnx-x11-6:amd64 (2:3.5.99.23-1build1) ... Removing libx2go-utils-perl (4.1.0.3-5) ... Removing nx-x11-common (2:3.5.99.23-1build1) ... Removing x2goserver-common (4.1.0.3-5) ... Processing triggers for man-db (2.9.1-1) ... Processing triggers for libc-bin (2.31-0ubuntu9.9) ... ############################
Then the reinstall, via "sudo apt install x2goserver x2goserver-xsession":
############################ root@noc /var/log/apt # sudo apt install x2goserver x2goserver-xsession Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: libnx-x11-6 libx2go-config-perl libx2go-log-perl libx2go-server-db-perl libx2go-server-perl libx2go-utils-perl libxcompshad3 nx-x11-common nxagent x2goserver-common x2goserver-x2goagent Suggested packages: rdesktop Recommended packages: x11-xfs-utils x2goserver-extensions x2goserver-fmbindings x2goserver-printing The following NEW packages will be installed: libnx-x11-6 libx2go-config-perl libx2go-log-perl libx2go-server-db-perl libx2go-server-perl libx2go-utils-perl libxcompshad3 nx-x11-common nxagent x2goserver x2goserver-common x2goserver-x2goagent x2goserver-xsession The following held packages will be changed: x2goserver x2goserver-xsession 0 upgraded, 13 newly installed, 0 to remove and 25 not upgraded. Need to get 2,295 kB of archives. After this operation, 7,697 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 x2goserver-common all 4.1.0.3-5 [10.9 kB] Get:2 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libx2go-config-perl all 4.1.0.3-5 [5,508 B] Get:3 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libx2go-log-perl all 4.1.0.3-5 [5,584 B] Get:4 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libx2go-utils-perl all 4.1.0.3-5 [6,372 B] Get:5 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libx2go-server-db-perl amd64 4.1.0.3-5 [20.6 kB] Get:6 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libx2go-server-perl all 4.1.0.3-5 [11.7 kB] Get:7 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 nx-x11-common all 2:3.5.99.23-1build1 [36.0 kB] Get:8 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libnx-x11-6 amd64 2:3.5.99.23-1build1 [594 kB] Get:9 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 libxcompshad3 amd64 2:3.5.99.23-1build1 [42.4 kB] Get:10 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 nxagent amd64 2:3.5.99.23-1build1 [1,469 kB] Get:11 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 x2goserver-x2goagent amd64 4.1.0.3-5 [11.0 kB] Get:12 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 x2goserver amd64 4.1.0.3-5 [74.4 kB] Get:13 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 x2goserver-xsession all 4.1.0.3-5 [8,044 B] Fetched 2,295 kB in 0s (10.4 MB/s) Preconfiguring packages ... Selecting previously unselected package x2goserver-common. (Reading database ... 162481 files and directories currently installed.) Preparing to unpack .../00-x2goserver-common_4.1.0.3-5_all.deb ... Unpacking x2goserver-common (4.1.0.3-5) ... Selecting previously unselected package libx2go-config-perl. Preparing to unpack .../01-libx2go-config-perl_4.1.0.3-5_all.deb ... Unpacking libx2go-config-perl (4.1.0.3-5) ... Selecting previously unselected package libx2go-log-perl. Preparing to unpack .../02-libx2go-log-perl_4.1.0.3-5_all.deb ... Unpacking libx2go-log-perl (4.1.0.3-5) ... Selecting previously unselected package libx2go-utils-perl. Preparing to unpack .../03-libx2go-utils-perl_4.1.0.3-5_all.deb ... Unpacking libx2go-utils-perl (4.1.0.3-5) ... Selecting previously unselected package libx2go-server-db-perl. Preparing to unpack .../04-libx2go-server-db-perl_4.1.0.3-5_amd64.deb ... Unpacking libx2go-server-db-perl (4.1.0.3-5) ... Selecting previously unselected package libx2go-server-perl. Preparing to unpack .../05-libx2go-server-perl_4.1.0.3-5_all.deb ... Unpacking libx2go-server-perl (4.1.0.3-5) ... Selecting previously unselected package nx-x11-common. Preparing to unpack .../06-nx-x11-common_2%3a3.5.99.23-1build1_all.deb ... Unpacking nx-x11-common (2:3.5.99.23-1build1) ... Selecting previously unselected package libnx-x11-6:amd64. Preparing to unpack .../07-libnx-x11-6_2%3a3.5.99.23-1build1_amd64.deb ... Unpacking libnx-x11-6:amd64 (2:3.5.99.23-1build1) ... Selecting previously unselected package libxcompshad3:amd64. Preparing to unpack .../08-libxcompshad3_2%3a3.5.99.23-1build1_amd64.deb ... Unpacking libxcompshad3:amd64 (2:3.5.99.23-1build1) ... Selecting previously unselected package nxagent. Preparing to unpack .../09-nxagent_2%3a3.5.99.23-1build1_amd64.deb ... Unpacking nxagent (2:3.5.99.23-1build1) ... Selecting previously unselected package x2goserver-x2goagent. Preparing to unpack .../10-x2goserver-x2goagent_4.1.0.3-5_amd64.deb ... Unpacking x2goserver-x2goagent (4.1.0.3-5) ... Preparing to unpack .../11-x2goserver_4.1.0.3-5_amd64.deb ... Unpacking x2goserver (4.1.0.3-5) ... Preparing to unpack .../12-x2goserver-xsession_4.1.0.3-5_all.deb ... Unpacking x2goserver-xsession (4.1.0.3-5) ... Setting up x2goserver-common (4.1.0.3-5) ... Group x2gouser already exists. User x2gouser already exists. usermod: no changes Setting up libx2go-config-perl (4.1.0.3-5) ... Setting up nx-x11-common (2:3.5.99.23-1build1) ... Setting up libx2go-log-perl (4.1.0.3-5) ... Setting up libx2go-utils-perl (4.1.0.3-5) ... Setting up libnx-x11-6:amd64 (2:3.5.99.23-1build1) ... Setting up libxcompshad3:amd64 (2:3.5.99.23-1build1) ... Setting up libx2go-server-db-perl (4.1.0.3-5) ... Setting up nxagent (2:3.5.99.23-1build1) ... Setting up libx2go-server-perl (4.1.0.3-5) ... Setting up x2goserver-x2goagent (4.1.0.3-5) ... Setting up x2goserver (4.1.0.3-5) ... Setting up x2goserver-xsession (4.1.0.3-5) ... Processing triggers for systemd (245.4-4ubuntu3.21) ... Processing triggers for man-db (2.9.1-1) ... Processing triggers for libc-bin (2.31-0ubuntu9.9) ... root@noc /var/log/apt # ############################
This story has an happy ending: I have obtained back the control of my server (well, actually a KDE destkop install), and this is wonderful.
So, as promised, I'm gonna donate via https://www.betterplace.org/en/donate/ww-sparkasse-ulm/projects/111056, inviting everyone else reading to follow me, because you guys deserve that.
All the best, and - one more time - thanks!
PS Anyway Discover lists me tons of packets available for updates. There is not/any x2go packet listed anymore, as it happened two days ago. Would it be safe proceeding with that (huge) updates session?