Looking at the function it only extracts the tar file, see http://bazaar.launchpad.net/~ubuntu-core-dev/ubuntu-release-upgrader/trunk/view/head:/DistUpgrade/DistUpgradeFetcherCore.py#L133
Looking at the function it only extracts the tar file, see http:// bazaar. launchpad. net/~ubuntu- core-dev/ ubuntu- release- upgrader/ trunk/view/ head:/DistUpgra de/DistUpgradeF etcherCore. py#L133