root@fuzzyhost:~# do-release-upgrade
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [198 B]
Get:2 Upgrade tool [1205 kB]
Fetched 1206 kB in 6s (76.9 kB/s)
authenticate 'raring.tar.gz' against 'raring.tar.gz.gpg'
extracting 'raring.tar.gz'
Traceback (most recent call last):
  File "/tmp/ubuntu-release-upgrader-1zit68/raring", line 6, in <module>
    from DistUpgrade.DistUpgradeMain import main
  File "/tmp/ubuntu-release-upgrader-1zit68/DistUpgrade/DistUpgradeMain.py", line 27, in <module>
    import apt
ImportError: No module named apt



root@fuzzyhost:~# apt-get install apt
Reading package lists... Done
Building dependency tree
Reading state information... Done
apt is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.