OK. I have managed to get the SDK installed now. So my next task it to repeat it again on a clean VM and this time record exactly what is wrong and what actually fixed it. What I think fixed it was purging the ppa (using ppa-purge) after the installation of qtcreator-plugin-ubuntu_2.8.1.2bzr90precise0_amd64.deb and then the command "sudo apt-get install ubuntu-sdk" worked. But I want to confirm this.
OK. I have managed to get the SDK installed now. So my next task it to repeat it again on a clean VM and this time record exactly what is wrong and what actually fixed it. What I think fixed it was purging the ppa (using ppa-purge) after the installation of qtcreator- plugin- ubuntu_ 2.8.1.2bzr90pre cise0_amd64. deb and then the command "sudo apt-get install ubuntu-sdk" worked. But I want to confirm this.