Comment 12 for bug 996379

this seems to be a duplicate bug of these bugs:
Update manager doesn't calculate free space correctly for distribution upgrade
https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/986272
[Master] package failed to install/upgrade: package is already installed and configured
https://bugs.launchpad.net/ubuntu/+source/dpkg/+bug/541595