[Aptitude-devel] Bug#991268: aptitude should provide an option to install packages from lower priority repos (backports, experimental) if the runtime dependency specify a version that can be satisfied only with these repos

[Pirate Praveen]

Package: aptitude
Severity: important
Version: 0.8.13-3

aptitude already provide such an option for choosing build dependencies 
when building for backports or experimental, it would be great if there 
is an option for runtime dependencies as well.

Currently we have 3 options,

1. aptitude -t buster-backports/experimental install foo - which will 
make priority of every package 500 and can create problems if 
conflicting newer versions are in buster-backports or experimental.
2. aptitude install foo bar/experimental - this works when we have 
small number of dependencies, but for packages with large number of 
dependencies this can be very inconvenient and hard.

For example, to install diaspora, I have to use

apt install diaspora ruby-marcel/bullseye-backports-staging 
ruby-autoprefixer-rails/bullseye-backports-staging \
ruby-responders/bullseye-backports-staging 
unicorn/bullseye-backports-staging \
ruby-unicorn-worker-killer/bullseye-backports-staging \
ruby-devise-two-factor/bullseye-backports-staging 
ruby-sidekiq/bullseye-backports-staging \
ruby-configurate/bullseye-backports-staging 
ruby-nokogiri/bullseye-backports-staging \
ruby-open-graph-reader/bullseye-backports-staging 
ruby-secure-headers/bullseye-backports-staging \
ruby-hamlit/bullseye-backports-staging 
ruby-rotp/bullseye-backports-staging \
ruby-zip/bullseye-backports-staging 
diaspora-common/bullseye-backports-staging \
ruby-toml-rb/bullseye-backports-staging 
ruby-rails/bullseye-backports-staging \
ruby-railties/bullseye-backports-staging 
ruby-actioncable/bullseye-backports-staging \
ruby-actioncable/bullseye-backports-staging 
ruby-actionmailer/bullseye-backports-staging \
ruby-actionpack/bullseye-backports-staging 
ruby-actiontext/bullseye-backports-staging \
ruby-actionview/bullseye-backports-staging 
ruby-activejob/bullseye-backports-staging \
ruby-activemodel/bullseye-backports-staging 
ruby-activerecord/bullseye-backports-staging \
ruby-activestorage/bullseye-backports-staging 
ruby-activesupport/bullseye-backports-staging \
ruby-actionmailbox/bullseye-backports-staging

buster-backports-staging is unofficially suite as bullseye-backports is 
not officially opened yet.

3. Use apt pinning, I currently use this for gitlab, 
https://salsa.debian.org/fasttrack-team/gitlab-apt-pin-preferences/-/blob/bullseye-fasttrack/99gitlab

but installing pin preferences is considered a lintian error.

So please provide an option that will choose packages with a lower 
priority if the runtime dependency has a requirement that can be 
satisfied with a lower priority packages.