Comment 8 for bug 1378245

The command, when properly given the correct sources.list etc, does only update the PPA archive information, after which apt dist-upgrade should do the correct thing.

I thought citrain actually used this already. If so, I think the main remaining citrain problem for eg. Qt testing is that it (maybe?) uses only 'upgrade' which then fails when there'd be new packages to be installed as new dependencies from the package versions in the PPA.

Or, alternatively to the 'upgrade' possibility (vs. more correct dist-upgrade which should be fine if only PPA packages are considered as the ones to be upgrades), the cause of the problem might be the fact that normal archive information is missing on a fresh flash. And it'd be only obtainable by a full apt update, making it impossible to combine this feature when new packages are needed from the archive.

Nevertheless, the citrain tool is not often usable with a big Qt landing.