/etc/adduser.conf.dpkg-save created by postinst since 3.121ubuntu1

[Tomáš Virtus]

Since version 3.121ubuntu1 adduser's postinst script creates /etc/adduser.conf.dpkg-save file on debootstrap's root filesystem, that is, even when /etc/adduser.conf doesn't exist prior to package installation.

Because of the change below the postinst script changes packaged /etc/adduser.conf and creates /etc/adduser.conf.dpkg-save as a backup:

  - Enable private home directories by default (LP: #48734)
    + Set DIR_MODE=0750 in the default adduser.conf
    + Change the description and default value to select private home
      directories by default in debconf template
    + Change the DIR_MODE when private home directories is configured via
      debconf from 0751 to 0750 to ensure files are truly private

The .dpkg-save file shouldn't be present on debootstrapped system.

[Alex Murray (alexmurray)]

From what I can see of this postinst this looks to be a bug from adduser in debian itself - and would appear to come from https://salsa.debian.org/debian/adduser/-/blob/master/debian/postinst#L33 - ie. if the default value is unchanged then an /etc/adduser.conf.dpkg-save is always generated when the value of DIR_MODE is appended to /etc/adduser.conf.

Can you confirm if this also occurs when debootstrapping a system from debian?

[Tomáš Virtus (virtustom)]

You are right, this happens even when deboostrapping Debian. Reported against adduser' in Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1012492

[Launchpad Janitor (janitor)]

This bug was fixed in the package adduser - 3.129ubuntu1

---------------
adduser (3.129ubuntu1) lunar; urgency=medium

  * Merge from Debian unstable (LP: #1873519, #1977710). Remaining changes:
    - Add support for encrypting home directories:
      + adduser: Add --encrypt-home option, which calls ecryptfs-setup-private
        for the hard work.
      + doc/adduser.8: document the --encrypt-home option
      + debian/control: suggest ecryptfs-utils >= 67-1
      + deluser: remove all of /var/lib/ecryptfs/$user with --remove-home
    - extrausers support for adduser and gpasswd (LP: #1323732)
    - Add support for ZFS home directories (LP: #1873263)
    - Enable private home directories by default (LP: #48734)
      + Set DIR_MODE=0750 and SYS_DIR_MODE=0750 in the default adduser.conf
   * Rename NAME_REGEX_SYSTEM to SYS_NAME_REGEX
     - AdduserCommon.pm, adduser.conf: Change default SYS_NAME_REGEX to allow
       uppercase letters in the names of system users.
   * Removed changes (superseded by Debian):
    - AdduserCommon.pm, adduser, adduser.8, adduser.conf.5: Allow uppercase
      letters in the names of system users. This is done by having a separate
      NAME_REGEX_SYSTEM configuration setting which applies when --system is
      specified.

adduser (3.129) unstable; urgency=medium

  * improve parameter interpretation for adduser.
    Thanks to Boris Kolpackov (Closes: #1018861)

adduser (3.128) unstable; urgency=medium

  [ Marc Haber ]
  * increase timeouts, reduce number of tests for delgroup_perf.t
    they have timed out in Debian infrastructure
  * even the legacy testsuite needs cron
  * Write defaults explicitly in configuration file templates.
    Thanks to Christoph Anton Mitterer (Closes: #1017888)
  * skip most of the version checks in preinst
    Thanks to Vincent Lefevre (Closes: #1017912)
  * document that the --ingroup group must exist
  * fix handling of explicitly set --uid and --gid.
    Thanks to Samuel Thibault (Closes: #1017952)

  [ Benjamin Drung ]
  * Document parameter for checkname function

adduser (3.127) unstable; urgency=low

  [ Jason Franklin ]
  * Document the intent of the --no-create-home option (Closes: #152195)

  [ Marc Haber ]
  * create home directory with primary group of the user (Closes: #1017694)
  * update and extend README

adduser (3.126) experimental; urgency=medium

  * more clear conffile handling in debian/preinst.
    Thanks to Simon McVittie (Closes: #1016574)
  * add postrm script cleaning up better after purge
  * add a Debian README, move too long DIR_MODE explanation from
    NEWS.Debian to README.

adduser (3.125) experimental; urgency=medium

  [ Marc Haber ]
  * remove debconf. (Closes: #57280, #398802)
  * install (add|del)user.conf as examples.
  * install adduser.conf as dpkg-conffile directly to /etc.
    (Closes: #541620)
  * remove postinst/postrm. (Closes: #1012492)

  [ Jason Franklin ]
  * Remove the unused "get_users_groups" subroutine. (Closes: #1015907)

  [ Matt Barry ]
  * Do not check for group being empty on 'delgroup'. (Closes: #682156)

adduser (3.124) experimental; urgency=medium

  * experimental upload
  * implement new USERS_GROUP semantics
    * ...