[DRE-maint] Bug#1150190: ruby-redis: FTBFS in unstable with ruby-redis-client 0.31.0-1: gemspec requires redis-client = 0.30.1

[Ajayi Olatunji O.]

Package: ruby-redis
Version: 6.0.0-1
Severity: serious

Dear Maintainer,

ruby-redis 6.0.0-1 fails to build from source in unstable now that 
ruby-redis-client 0.31.0-1 is in unstable (accepted 2026-10-06). The 
same incompatibility makes ruby-redis unusable at run time. I set the 
severity to serious because the release critical issues document says: 
"Packages must be buildable within the same release."

The requirement comes from upstream. redis.gemspec in 
ruby-redis_6.0.0.orig.tar.gz says:

   line 47: # Pinned to an exact redis-client version: redis-rb couples 
tightly to redis-client internals
   line 52: s.add_runtime_dependency('redis-client', '0.30.1')

Build failure (sbuild, unstable chroot, ruby-redis-client 0.31.0-1 
installed, finished 2026-10-06T18:07Z, Fail-Stage: build):

   Checking Rubygems dependency resolution on ruby3.3
   Could not find 'redis-client' (= 0.30.1) among 117 total gem(s) 
(Gem::MissingSpecError)
   dh_auto_test: error: dh_ruby --test returned exit code 1

Run time reproduction in a clean unstable chroot (apt-get install ruby 
ruby-redis, then ruby -e "require 'redis'"):

   Could not find 'redis-client' (= 0.30.1) ... at: 
/usr/share/rubygems-integration/all/specifications/redis-6.0.0.gemspec 
(Gem::MissingSpecError)
   cannot load such file -- redis (LoadError)

The installed redis-6.0.0.gemspec contains:

   s.add_runtime_dependency(%q<redis-client>.freeze, ["= 0.30.1".freeze])

The binary package declares (apt-cache show ruby-redis in unstable):

   Depends: ruby:any, ruby-redis-client (>= 0.30.1)

so apt accepts ruby-redis-client 0.31.0-1, while RubyGems rejects it. 
debian/control in the source package lists only Depends: ruby:any, so I 
assume the redis-client dependency is generated during the build; I have 
not checked how the exact upstream requirement becomes (>=).

Testing still has ruby-redis-client 0.30.1-1 and is consistent. The 
tracker shows autopkgtests for ruby-redis, ruby-redis-client, 
ruby-redis-cluster-client and ruby-sidekiq triggered for 0.31.0-1, with 
no results yet.

The newest upstream redis gem is 6.0.0, released 2026-07-31 
(rubygems.org versions API), which is the version already packaged. So 
there is no newer redis release available to package for redis-client 
0.31.0. I did not check for unreleased upstream work.

Impact: packages that build or test with the redis gem fail in unstable. 
I noticed this while updating ruby-classifier-reborn, whose Redis tests 
error with NameError: uninitialized constant ...::Redis instead of skipping.

I do not know which side should change (keeping ruby-redis-client 
0.31.0-1 out of unstable until a compatible redis release exists, or 
another solution), so I leave that to you. I did not find an existing 
bug for this: src:ruby-redis-client has no reports, and src:ruby-redis 
has only #1093118, whose title concerns ruby-fakeredis.

Thank you for maintaining these packages.

Ajayi Olatunji