Comment 20 for bug 1979128

Thanks Lucas and Andreas. I verified new bsfilter package.

# install bsfilter

root@sdbm:~# cat <<EOF >/etc/apt/sources.list.d/ubuntu-$(lsb_release -cs)-proposed.list
# Enable Ubuntu proposed archive
deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed restricted main multiverse universe
EOF
root@sdbm:~# cat <<EOF >/etc/apt/preferences.d/proposed-updates
# Configure apt to allow selective installs of packages from proposed
Package: *
Pin: release a=$(lsb_release -cs)-proposed
Pin-Priority: 400
EOF
root@sdbm:~# apt update
root@sdbm:~# apt policy bsfilter
bsfilter:
  Installed: (none)
  Candidate: 1:1.0.19-2.1
  Version table:
     1:1.0.19-2.1ubuntu0.1 400
        400 http://archive.ubuntu.com/ubuntu jammy-proposed/universe amd64 Packages
     1:1.0.19-2.1 500
        500 http://archive.ubuntu.com/ubuntu jammy/universe amd64 Packages
root@sdbm:~# apt install -t jammy-proposed bsfilter
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  fonts-lato javascript-common libjs-jquery libruby3.0 rake ruby ruby-net-telnet ruby-rubygems ruby-sdbm ruby-webrick ruby-xmlrpc ruby3.0 rubygems-integration unzip zip
Suggested packages:
  ruby-mecab ruby-qdbm apache2 | lighttpd | httpd ri ruby-dev bundler
The following NEW packages will be installed:
  bsfilter fonts-lato javascript-common libjs-jquery libruby3.0 rake ruby ruby-net-telnet ruby-rubygems ruby-sdbm ruby-webrick ruby-xmlrpc ruby3.0 rubygems-integration unzip zip
0 upgraded, 16 newly installed, 0 to remove and 31 not upgraded.
Need to get 9008 kB of archives.
After this operation, 39.0 MB of additional disk space will be used.
(snip)
  => install ruby-sdbm too.

# test bsfilter
root@sdbm:~# touch foo
root@sdbm:~# bsfilter --sub-clean --add-spam --insert-flag --insert-probability --update foo
root@sdbm:~# echo $?
0