Comment 9 for bug 446552

after downloading the content of http://changelogs.ubuntu.com/meta-release manually to /var/lib/update-manager/meta-release, the script runs a little bit further:

Debug output of do-release-upgrade now shows:

$ sudo DEBUG_UPDATE_MANAGER=1 /usr/bin/do-release-upgrade
Checking for a new ubuntu release
MetaRelease.__init__() useDevel=False useProposed=False
/etc/update-manager/meta-release: http://changelogs.ubuntu.com/meta-release
/etc/update-manager/meta-release: http://changelogs.ubuntu.com/meta-release-lts
/etc/update-manager/meta-release: -development
/etc/update-manager/meta-release: -proposed
metarelease-uri: http://changelogs.ubuntu.com/meta-release
MetaRelease.download()
have self.metarelease_information
MetaRelease.parse()
current dist name: 'jaunty'
new dist: <UpdateManager.Core.MetaRelease.Dist object at 0xb78780ac>
trying to find suitable mirror
mirror_from_sources_list: jaunty
trying to find suitable mirror
mirror_from_sources_list: jaunty
Failed Upgrade tool signature
Failed Upgrade tool
Done downloading
Failed to fetch
Fetching the upgrade failed. There may be a network problem.