I get similar errors when I try to just install the plasticscm-proxy-server:
sudo apt-get install plasticscm-proxy-server
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
plasticscm-proxy-server : Depends: liblttng-ust0 but it is not installable
Depends: libssl1.1 but it is not installable or
libssl1.0.0 but it is not installable
Depends: libicu52 but it is not installable or
libicu55 but it is not installable or
libicu57 but it is not installable or
libicu60 but it is not installable or
libicu63 but it is not installable or
libicu66 but it is not installable or
libicu67 but it is not installable
E: Unable to correct problems, you have held broken packages.
We have a client who would like us to use the proxy server to speed up builds and I would prefer to not to have to reinstall an older version of Ubuntu on this server or add packages from an older version.
Is there any update on the progress of adding Ubuntu 22.04 LTS support? We only need the proxy server, not any Plastic GUI toolsm so maybe you might be able to release an update for just that sooner?