Comment 16 for bug 277389

Thanks. There's not much evidence in it. The term.log is empty and there's no apt-term.log. You may need to user superuser privileges in order to read that file.

It seems that kubuntu-desktop as been held from a previous install.

Can you please try the following command and report the output ( or attach the file /var/log/apt/term.log )
sudo apt-get install kubuntu-desktop

Thanks.