Upgrade from Feisty to Gutsy Gibbon fails

[Augusto]

sudo do-release-upgrade
Checking for a new ubuntu release
Done Upgrade tool signature
Done Upgrade tool
Done downloading
extracting '/tmp/tmpTbAxdx/gutsy.tar.gz'
authenticate '/tmp/tmpTbAxdx/gutsy.tar.gz' against '/tmp/tmpTbAxdx/gutsy.tar.gz.gpg'

Lendo cache

Verificando o Gerenciador de Pacotes
Reading package lists: Done/non-free Packages: 94 94 ges: 94
Reading state information: Done
Reading state information: Done
Reading state information: Done

Ocorreu um erro fatal
Please report this as a bug and include the files /var/log/dist-upgrade/main.log and /var/log/dist-upgrade/apt.log in your report. The upgrade aborts now.
Your original sources.list was saved in /etc/apt/sources.list.distUpgrade.
Traceback (most recent call last):

  File "/tmp/tmpTbAxdx/gutsy", line 59, in <module>
    app.run()

  File "/tmp/tmpTbAxdx/DistUpgradeControler.py", line 1346, in run
    self.fullUpgrade()

  File "/tmp/tmpTbAxdx/DistUpgradeControler.py", line 1251, in fullUpgrade
    if not self.getRequiredBackports():

  File "/tmp/tmpTbAxdx/DistUpgradeControler.py", line 1140, in getRequiredBackports
    outfile = open(os.path.join(apt_pkg.Config.FindDir("Dir::Etc::sourceparts"), sourceslistd), "w")

IOError: [Errno 2] No such file or directory: '/etc/apt/sources.list.d/prerequists-sources.list'