The Debian package of DaCHS creates a "maintainer" account, dachsroot.
It is the default owner of data and description files.  Other accounts
are usable for feeding the database, too, but all such accounts must be
members of the gavo group.

The postinst scripts try to run gavo upgrade to incorporate schema
changes introduced in the new version.  This, however, may fail
in many ways, and this should not block the upgrade process, hence such
failures are ignored.

Hence, after an upgrade, it's usually a good idea to run gavo upgrade
again and watch for errors.  There is no risk running it multiple times.
