Ubuntu SDK не устанавливается 12.04

asim@ubuntu:~$ sudo apt-get install ubuntu-sdk
Reading package lists... Done
Building dependency tree       
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:
 ubuntu-sdk : Depends: qtcreator-plugin-ubuntu-cordova but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
asim@ubuntu:~$ 

Я решил установить qtcreator-plugin-ubuntu-cordova отдельно, затем:

asim@ubuntu:~$ sudo apt-get install qtcreator-plugin-ubuntu-cordova
Reading package lists... Done
Building dependency tree       
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:
 qtcreator-plugin-ubuntu-cordova : Depends: qtcreator-plugin-ubuntu (= 2.8.1bzr56precise0) but 2.8.1bzr57precise0 is to be installed
E: Unable to correct problems, you have held broken packages.
asim@ubuntu:~$ 

Здесь я подумал, что принудительное использование правильной версии пакета будет работать нормально, но еще раз:

asim@ubuntu:~$ sudo apt-get install qtcreator-plugin-ubuntu-cordova =2.8.1bzr57precise0
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package 
asim@ubuntu:~$ 

Кто-нибудь может мне помочь? Я занимался веб-разработкой на php, но решил попробовать разработку программного обеспечения на Ubuntu.

Редактировать

apt-cache policy qtcreator-plugin-ubuntu-cordova qtcreator-plugin-ubuntu ubuntu-sdk дает:

root@ubuntu:/home/asim# apt-cache policy qtcreator-plugin-ubuntu-cordova qtcreator-plugin-ubuntu ubuntu-sdk
qtcreator-plugin-ubuntu-cordova:
  Installed: (none)
  Candidate: 2.8.1bzr56precise0
  Version table:
     2.8.1bzr56precise0 0
        500 http://ppa.launchpad.net/ubuntu-sdk-team/ppa/ubuntu/ precise/main amd64 Packages
qtcreator-plugin-ubuntu:
  Installed: 2.8.1bzr57precise0
  Candidate: 2.8.1bzr57precise0
  Version table:
 *** 2.8.1bzr57precise0 0
        500 http://ppa.launchpad.net/ubuntu-sdk-team/ppa/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status
ubuntu-sdk:
  Installed: (none)
  Candidate: 1.009~sdkppa~precise1~test6
  Version table:
     1.009~sdkppa~precise1~test6 0
        500 http://ppa.launchpad.net/ubuntu-sdk-team/ppa/ubuntu/ precise/main amd64 Packages