[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.]

Additional information, following a suggestion to test a relaxed 
requirement.

1. Package build. I took ruby-redis_6.0.0-1.dsc from the archive and 
added a quilt patch that changes line 52 of redis.gemspec from '0.30.1' 
to '>= 0.30.1' (full patch below). sbuild in an unstable chroot with 
ruby-redis-client 0.31.0-1 installed finished with Status: successful 
and Lintian: pass. The build log says "Run tests for ruby3.3: no test 
suite!", so this step ran no tests.

2. Upstream test suite. I cloned upstream redis-rb at tag v6.0.0 and 
made the same change to redis.gemspec. With redis-client 0.31.0 and 
hiredis-client 0.31.0 installed from rubygems.org, I ran upstream's 
tests as its CI workflow (.github/workflows/test.yaml) does: Redis 8.8.0 
servers from upstream's docker-compose.yml, Ruby 3.3.8, and the test 
groups redis, distributed, sentinel, modules and cluster, each under 
RESP3 and RESP2 with the ruby and hiredis drivers.
Result: 0 failures and 0 errors in every run. The redis group ran 656 
tests, distributed 431, sentinel 20, modules 264 and cluster 488, with 
skips as the suite defines them. With the original pin (redis-client 
0.30.1) the first four groups also passed, with the same counts.

Limits of this result: I tested one Ruby version (3.3.8) and one Redis 
version (8.8.0), not the full CI matrix, and I ran the groups one at a 
time with rake instead of in one command. I used the redis-client gem 
from rubygems.org, not the Debian package ruby-redis-client 0.31.0-1, 
and I did not compare the two. These results do not show that the Debian 
package builds and passes its own tests with a relaxed dependency.

The pin is deliberate upstream. The comment above line 52 in 
redis.gemspec says: "Bump deliberately and re-run the full suite." I 
therefore offer the patch and the results as evidence only, not as a 
recommended change. I have also asked upstream about redis-client 
0.31.0: https://github.com/redis/redis-rb/issues/1398

Patch used for the test:

Index: ruby-redis-6.0.0/redis.gemspec
===================================================================
--- ruby-redis-6.0.0.orig/redis.gemspec
+++ ruby-redis-6.0.0/redis.gemspec
@@ -49,5 +49,5 @@
    # constraint can change semantics under a stable redis release. Bump 
deliberately and re-run
    # the full suite. Note hiredis-client versions in lockstep (it 
requires redis-client `= x.y.z`).
-  s.add_runtime_dependency('redis-client', '0.30.1')
+  s.add_runtime_dependency('redis-client', '>= 0.30.1')
  end

Ajayi Olatunji