Take note of package status before an upgrade and help with downgrading if something went wrong.
Before an upgrade, take note of the system status:
debcya --save=`date +%Y%m%d`.state
If something went wrong, you can redownload the packages you had installed on that day. Use --debs to download all binaries that you had installed for one or more given source packages:
debcya --state=20160106.state --debs network-manager