When installing ThinLinc, it's common to "scp -r" the server-cd directory from, for example, a nightly build. If you later do the same operation again, the server-cd directory will contain duplicate packages. The installation program currently does not detect this situation: It says, basically, that "VSM is up to date and VSM will be upgraded". Also, the installer does not detect if a certain package is missing. I think this problem can be fixed quite easily, by modifying glob_relative to verify that there's exactly one match.
Note that this only happens for development builds as the directories include the version number.