Updating from 3.7.16 to 3.7.18 in linux

OK, let me see if I got your situation correct. You have the following directories

~/vassal -+- VASSAL-3.7.16
          |  + ...
          |  +- VASSAL.sh
          |  `- integration.sh
          +- VASSAL-3.7.18
             + ...
             +- VASSAL.sh
             `- integration.sh

When you execute VASSAL through desktop menus or by double-clicking a .vmod or similar, you will execute ~/vassal/VASSAL-3.7.16/VASSAL.sh - not ~/vassal/VASSAL-3.7.18/VASSAL.sh as intended.

Perhaps you could say how you did the How to Integrate VASSAL into the Linux Desktop procedure - for all users (option -s) or for a single user. Assuming you did if for a single user, then look at the content of

~/.local/share/applications/application-x-vassal.desktop

It most likely has lines like

Exec=/home/some/user/vassal/VASSAL-3.7.16/VASSAL.sh

To fix that, go into your VASSAL-3.7.16 directory and execute integration.sh with the -r option

$ cd ~/vassal/VASSAL-3.7.16
$ ./integration.sh -r 

Now to point to version 3.7.18, change directory to your VASSAL-3.7.18 directory and execute integration.sh with appropriate options

$ cd ~/vassal/VASSAL-3.7.18
$ ./integration.sh 

If you had over-written your 3.7.16 directory fully with 3.7.18, then you wouldn’t need to do the integration step again. Or if you had made a symbolic link to your current installation, and specified that as the installation directory for the integration.sh script, you wouldn’t need to redo it again. E.g.,

$ cd vassal
$ tar -xjf ../Downloads/VASSAL-linux-3.7.16.tar.bz2 
$ rm -f current
$ ln -s VASSAL-3.7.16 current 
$ ./integration.sh -v `pwd`/current  # Only needed once

and on update

$ cd vassal 
$ tar -xjf ../Downloads/VASSAL-linux-3.7.18.tar.bz2 
$ rm -f current
$ ln -s VASSAL-3.7.18 current 

As Pop!-OS is a derivative of Debian, you will in the not too distant future, be able to download a Debian package and install VASSAL through that. That will provide seamless installation and integration. You can try a preview vassal_3.7.19-SNAPSHOT-e8de2b8-1_all.deb. After downloading, simply do

$ sudo apt install ~/Downloads/vassal_3.7.19-SNAPSHOT-e8de2b8-1_all.deb

(make sure you run integration.sh -r first).

Yours,
Christian

Yours,
Christian