Package: debconf Version: 1.5.59 Followup-For: Bug #487300 I work on scripts for unattended installing OpenStack instance for testing (work-in-progress) and I use debconf preseeding using debconf-set-selections. https://anonscm.debian.org/cgit/users/zito-guest/setup-openstack.git/ Packages use dbconfig-common for database setup. The first such package in sequence is keystone in script os-controller-install. Before installing keystone I feed debconf-set-selections with e.g.
keystone keystone/database-type select mysql this creates following record in config.dat file Name: keystone/database-type Template: keystone/database-type Value: mysql Owners: keystone Flags: seen and record in templates.dat file: Name: keystone/database-type Description: Dummy template Extended_description: This is a fake template used to pre-seed the debconf database. If you are seeing this, something is probably wrong. Type: select Owners: keystone/database-type After installing keystone, records are transformed into: config.dat contains: Name: keystone/database-type Template: dbconfig-common/database-type Value: mysql Owners: keystone Flags: seen Variables: database_types = sqlite3, mysql dbvendor = MySQL pkg = keystone templates.dat contains: Name: dbconfig-common/database-type Choices: ${database_types} Description: Database type to be used by ${pkg}: ... Type: select Owners: dbconfig-common/database-type, keystone/database-type So far so good, But because some values are removed from debconf database by postinst maintainer script (e.g. password of database admin) I need to preseed some values with keystone installed again so I can do unattended package removal. This second preseeding doesn't affect record in config.dat (because value is the same), but debconf-set-selections creates one more time "Dummy template". After purging the package keystone, this dummy value left in templates db. This dummy template (orphaned) now breaks the next try to preseed values again, because debconf-set-selections fails: error: Cannot find a question for keystone/database-type Dummy template must be removed, to preseed values again. Hope this helps a bit. Cheers -- Zito