When running install_server on a fresh system it prints the following to thinlinc-install.log: > 2022-04-27 11:12:45,583: *** ThinLinc installer started *** > 2022-04-27 11:12:45,583: Architecture: x86_64 > 2022-04-27 11:12:45,583: Distribution: Ubuntu > 2022-04-27 11:12:45,583: Package format: deb > 2022-04-27 11:12:46,336: Analyzing upgrade path... > 2022-04-27 11:12:46,336: Checking 'thinlinc-server_4.14.0post-2594_amd64.deb'... > 2022-04-27 11:12:46,365: Failed to get information about package 'thinlinc-server' > 2022-04-27 11:12:46,365: dpkg-query: no packages found matching thinlinc-server > 2022-04-27 11:12:46,383: Failed to get information about package 'thinlinc-vnc-server' > 2022-04-27 11:12:46,383: dpkg-query: no packages found matching thinlinc-vnc-server > 2022-04-27 11:12:46,394: Failed to get information about package 'thinlinc-vsm' > 2022-04-27 11:12:46,394: dpkg-query: no packages found matching thinlinc-vsm > 2022-04-27 11:12:46,405: Failed to get information about package 'thinlinc-rdesktop' > 2022-04-27 11:12:46,405: dpkg-query: no packages found matching thinlinc-rdesktop > 2022-04-27 11:12:46,423: Failed to get information about package 'thinlinc-tladm' > 2022-04-27 11:12:46,423: dpkg-query: no packages found matching thinlinc-tladm > 2022-04-27 11:12:46,434: Failed to get information about package 'thinlinc-webaccess' > 2022-04-27 11:12:46,435: dpkg-query: no packages found matching thinlinc-webaccess > 2022-04-27 11:12:46,446: Failed to get information about package 'thinlinc-tlmisc-libs32' > 2022-04-27 11:12:46,446: dpkg-query: no packages found matching thinlinc-tlmisc-libs32 > 2022-04-27 11:12:46,457: Failed to get information about package 'thinlinc-tlmisc-libs' > 2022-04-27 11:12:46,457: dpkg-query: no packages found matching thinlinc-tlmisc-libs > 2022-04-27 11:12:46,469: Failed to get information about package 'thinlinc-tlmisc' > 2022-04-27 11:12:46,469: dpkg-query: no packages found matching thinlinc-tlmisc > 2022-04-27 11:12:46,480: Failed to get information about package 'thinlinc-tlprinter' > 2022-04-27 11:12:46,480: dpkg-query: no packages found matching thinlinc-tlprinter > 2022-04-27 11:12:46,480: Version to install: 4.14.0post-2594_amd64 > 2022-04-27 11:12:46,480: Current version(s): > 2022-04-27 11:12:46,480: Packages to install: thinlinc-server_4.14.0post-2594_amd64.deb > 2022-04-27 11:12:47,247: Installing package(s): thinlinc-server_4.14.0post-2594_amd64.deb > 2022-04-27 11:12:50,527: Installation complete. > 2022-04-27 11:12:50,527: Starting tl-setup... The messages about "Failed to get information about package..." look confusing to me. I wouldn't be surprised if some admins got worried by reading those lines, it looks a bit like some type of error. Since it mentions thinlinc-rdesktop and other old package names I guess this is caused by some type of compatibility code in install_server. This information is not useful to the admin.
