I've tried installing the client on both Ubuntu 14.04 (x86) and 13.10 (ARM), and in both cases it fails to install by simply double clicking the client package. The application assigned to handle packages is Ubuntu Software Center, and it seems to delegate installation to aptd. No error messages or logs to tell you what goes wrong though. I also haven't tested any other package, so it might simply be horribly broken with any local package. Still, we should do something, even if that might only be to report a bug to Ubuntu.
Must have been a bug in Ubuntu that they've fixed. I tried it again on a fully updated 14.04 and it installs the client package just fine.
Installation on Ubuntu 14.04 works, but Software Centre complains (bug 5232).