"The value 'precise' is invalid for APT::Default-Release" when upgrading from precise to quantal via command line

[MarianoAbsatz]

launched from terminal window with: 'sudo do-release-upgrade', after it modified the repositories to point to quantal and do the 'apt-get update', it throwed the following on to the terminal:

A fatal error occurred

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 has aborted.
Your original sources.list was saved in
/etc/apt/sources.list.distUpgrade.

Traceback (most recent call last):

File "/tmp/update-manager-fxmFQA/quantal", line 10, in <module>
sys.exit(main())

File "/tmp/update-manager-fxmFQA/DistUpgrade/DistUpgradeMain.py",
line 240, in main
if app.run():

File
"/tmp/update-manager-fxmFQA/DistUpgrade/DistUpgradeController.py",
line 1764, in run
return self.fullUpgrade()

File
"/tmp/update-manager-fxmFQA/DistUpgrade/DistUpgradeController.py",
line 1681, in fullUpgrade
self.openCache(restore_sources_list_on_fail=True)

File
"/tmp/update-manager-fxmFQA/DistUpgrade/DistUpgradeController.py",
line 207, in openCache
return self._openCache(lock)

File
"/tmp/update-manager-fxmFQA/DistUpgrade/DistUpgradeController.py",
line 235, in _openCache
lock)

File "/tmp/update-manager-fxmFQA/DistUpgrade/DistUpgradeCache.py",
line 94, in __init__
apt.Cache.__init__(self, progress)

File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 102, in
__init__
self.open(progress)

File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 145, in
open
self._cache = apt_pkg.Cache(progress)

SystemError: E:The value 'precise' is invalid for
APT::Default-Release as such a release is not available in the
sources

[MarianoAbsatz (el-baby)]

attaching also apt.log as requested...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Stefan Tauner (stefanct)]

In my case I get it when upgrading to trusty... I presume because precise is no longer supported. Removing the Apt preference/directive «APT::Default-Release "precise";» e.g. in /etc/apt/apt.conf.d/ helps.

[Andrej Ricnik (a-ricnik)]

Thanks for the "workaround" Stefan Tauner.

I am (still) in the process of upgrading a whole bunch of machines from 12.04 to 14.04, and out of 8 boxes so far only one has displayed this behvaviour - your workaround worked a treat.

The interesting bit (for me, anyway) was that 6 of the machines were cloned of the same VMware template, and one of those 5 so far was the only one misbehaving.