[DRE-maint] Bug#1052025: redmine: upgrade from bullseye(-backports) to bookworm fails

[wim]

Package: redmine
Version: 5.0.4-5
Severity: normal
X-Debbugs-Cc: wim.bertels at ucll.be

Hello,

upgrading a relative pristine redmine instance from deb 11 to 12 fails 
with the following:

debian 11: redmine via bullseye-backports
debian 12: apt upgrade --without-new-pkgs step

"
Do you want to continue? [Y/n] 
Setting up redmine (5.0.4-5) ...
Don't run Bundler as root. Bundler can ask for sudo if it is needed, and installing your bundle as root
will break this application for all non-root users on this machine.
Could not find gem 'net-imap' in cached gems or installed locally.
dpkg: error processing package redmine (--configure):
 installed redmine package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 redmine
E: Sub-process /usr/bin/dpkg returned an error code (1)
"


-- System Information:
Debian Release: 12.1
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-25-cloud-amd64 (SMP w/1 CPU thread)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages redmine depends on:
ii  dbconfig-common                 2.0.24
ii  debconf [debconf-2.0]           1.5.82
ii  libjs-chart.js                  3.9.1+~0.2.1-2
ii  libjs-jquery                    3.6.1+dfsg+~3.5.14-1
ii  libjs-jquery-ui                 1.13.2+dfsg-1
ii  libjs-raphael                   2.3.0-4
ii  libruby2.7 [ruby-csv]           2.7.4-1+deb11u1
ii  redmine-pgsql                   5.0.4-5
ii  ruby                            1:2.7+2
ii  ruby-actionpack-action-caching  1.2.2-1
ii  ruby-actionpack-xml-parser      2.0.1-4
ii  ruby-addressable                2.8.1-1
ii  ruby-bundler                    2.3.15-2
ii  ruby-coderay                    1.1.3-8
ii  ruby-commonmarker               0.23.6-1~bpo11+1
ii  ruby-csv                        3.2.2-1
ii  ruby-html-pipeline              2.14.3-1
ii  ruby-i18n                       1.10.0-2
ii  ruby-jquery-rails               4.3.5-4
ii  ruby-mail                       2.7.1+dfsg1-2
ii  ruby-marcel                     1.0.1+dfsg-2
ii  ruby-mini-magick                4.11.0-1
ii  ruby-mini-mime                  1.1.1-2
ii  ruby-mocha                      1.16.1-1
ii  ruby-net-ldap                   0.17.0-1
ii  ruby-nokogiri                   1.13.5+dfsg-2~bpo11+1
ii  ruby-rack                       2.2.6.4-1
ii  ruby-rack-test                  2.0.2-2
ii  ruby-rails                      2:6.1.7.3+dfsg-1
ii  ruby-rails-dom-testing          2.0.3-4
ii  ruby-rails-observers            0.1.5-1.1
ii  ruby-rbpdf                      1.20.1-2
ii  ruby-redcarpet                  3.5.1-1
ii  ruby-request-store              1.5.1-1
ii  ruby-rmagick                    2.16.0-7
ii  ruby-roadie                     5.1.0-1
ii  ruby-roadie-rails               3.0.0-1
ii  ruby-rotp                       6.2.0-2
ii  ruby-rouge                      3.30.0-2
ii  ruby-rqrcode                    1.2.0-1
ii  ruby-sanitize                   6.0.0-1.1
ii  ruby-task-list                  2.3.2-2
ii  ruby-zip                        2.3.2-1

Versions of packages redmine recommends:
ii  passenger  5.0.30-1.2+deb11u1

Versions of packages redmine suggests:
pn  bzr         <none>
pn  cvs         <none>
pn  darcs       <none>
ii  git         1:2.30.2-1+deb11u2
pn  mercurial   <none>
pn  ruby-fcgi   <none>
ii  subversion  1.14.1-3+deb11u1

-- debconf information:
  redmine/instances/default/passwords-do-not-match:
  redmine/instances/default/dbconfig-reinstall: false
  redmine/instances/default/pgsql/method: TCP/IP
  redmine/instances/default/pgsql/manualconf:
  redmine/instances/default/db/app-user: redmine/instances/default at localhost
  redmine/instances/default/pgsql/authmethod-user: password
  redmine/current-instances: default
  redmine/default-language: en
* redmine/instances/default/database-type: pgsql
  redmine/instances/default/missing-db-package-error: abort
  redmine/instances/default/db/dbname: redmine_default
  redmine/instances/default/pgsql/authmethod-admin: ident
  redmine/instances/default/remote/port:
  redmine/instances/default/pgsql/changeconf: false
* redmine/instances/default/remote/host: localhost
  redmine/instances/default/internal/skip-preseed: true
  redmine/instances/default/upgrade-error: abort
  redmine/instances/default/install-error: abort
  redmine/instances/default/dbconfig-remove: true
  redmine/instances/default/remote/newhost: localhost
  redmine/instances/default/internal/reconfiguring: false
  redmine/instances/default/dbconfig-upgrade: true
* redmine/instances/default/dbconfig-install: true
  redmine/instances/default/purge: false
  redmine/instances/default/default-language: en
  redmine/instances/default/remove-error: abort
  redmine/instances/default/pgsql/admin-user: postgres
  redmine/instances/default/pgsql/no-empty-passwords:
  redmine/instances/default/upgrade-backup: true