Currently packages can add users and groups from their postinst scripts

The admin has no clear indication which users/groups might be created
when selecting packages to install

This does not meet the needs of all administrators.  For example:
- admin wants to use LDAP
- admin wants identical numeric IDs on all hosts to simplify use of
backup and rsync software (e.g. Bacula backs up file ownership numerically)

A more controlled solution might involve some of the following:

- in addition to checking for disk space, `apt-get install' would check
if all required users exist
- apt or dpkg would create the users required by the requested packages
- a setting in dpkg.cfg or apt.conf.d would allow the admin to disable
automatic user creation (in other words, apt-get install would abort
before any change to the system and just give the admin a list of
missing users to create manually)

Workaround: the admin can do things like creating a symlink from
(useradd|adduser) to /bin/false to ensure that dpkg fails on unexpected
user creation.  However, this potentially leaves packages partially
installed.

Control: clone -1 -2
Control: reassign -1 dpkg
Control: block -2 by -1

This is something dpkg would have to do.

Control: forcemerge 685734 -1

This was already filed in dpkg, merging.

Thanks,
Guillem