UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position

[Angel Guzman Maeso]

Upgrading from saucy to trusty, using "do-release-upgrade -d" I get this errors with the locale es_ES.UTF-8. Changing the locale to C or english it works.

"/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/DistUpgradeController.py",
line 1791, in run
return self.fullUpgrade()

File
"/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/DistUpgradeController.py",
line 1686, in fullUpgrade
if not self.updateSourcesList():

File
"/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/DistUpgradeController.py",
line 760, in updateSourcesList
if not self.rewriteSourcesList(mirror_check=True):

File
"/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/DistUpgradeController.py",
line 736, in rewriteSourcesList
logging.debug("entry '%s' was disabled (unknown mirror)" %
get_string_with_no_auth_from_source_entry(entry))

File "/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/utils.py", line
89, in get_string_with_no_auth_from_source_entry
return str(tmp)

File
"/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/sourceslist.py",
line 231, in __str__
return self.str().strip()

File
"/tmp/ubuntu-release-upgrader-7f54ti/DistUpgrade/sourceslist.py",
line 253, in str
line += " #"+self.comment

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position
33: ordinal not in range(128)
=== Command detached from window (Thu Oct 24 09:19:28 2013) ===
=== Command terminated with exit status 1 (Thu Oct 24 09:19:28 2013) ===

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: ubuntu-release-upgrader-core 1:0.205.1
ProcVersionSignature: Ubuntu 3.8.0-13.23-generic 3.8.3
Uname: Linux 3.8.0-13-generic i686
NonfreeKernelModules: fglrx
ApportVersion: 2.12.5-0ubuntu2
Architecture: i386
CrashDB: ubuntu
Date: Thu Oct 24 09:19:49 2013
InstallationDate: Installed on 2013-02-03 (262 days ago)
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: ubuntu-release-upgrader
UpgradeStatus: Upgraded to saucy on 2013-10-24 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2013-10-24 09:19:06.565726
 Log time: 2013-10-24 09:19:19.269817