/var/log/dist-upgrade/
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<span id="INSERTION_MARKER">I have been trying to upgrade my xubuntu laptop from 10.10 to 11.04 however always get this error message during the installation following which the installation has to be aborted:
<span id="INSERTION_MARKER">An unresolvable problem occurred while calculating the upgrade:Can not mark 'xubuntu-desktop' for upgrade This can be caused by: * Upgrading to a pre-release version of Ubuntu * Running the current pre-release version of Ubuntu * Unofficial software packages not provided by UbuntuIf none of this applies, then please report this bug against the 'update-manager' package and include the files in /var/log/dist-upgrade/ in the bug report.

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