[muhammadsamad99]

Checklist

• I have read the Contribution & Best practices Guide.
• My branch is up-to-date with the upstream master branch.
• The tests pass locally with my changes.
• I have added tests that prove my fix is effective or that my feature works(if appropriate).
• I have added necessary documentation (if appropriate).

Short description of what this resolves/which issues does this fix?:

• With BUNDLE_GEMFILE=Gemfile.next on Ruby 3.4.10 the app does not boot, so the Next-rails
  workflow cannot get past db:setup. Three independent causes, one commit each:
  1. cannot load such file -- csv: csv is a bundled (not default) gem since Ruby 3.4 and the
     Gemfile never declared it; the current lockfile only gets it through iso-639.
  2. cannot load such file -- observer: Gemfile.next.lock had drifted from Gemfile.lock
     (factory_bot 6.2.0, missing the connection_pool < 3 pin).
  3. Rails 8.0 raises on resource :contact, except: [:index, ...] because a singular resource
     has no index action (7.2 ignored it).

Changes proposed in this pull request:

• Declare gem 'csv'. Gemfile.lock keeps csv 3.3.5 and only gains the top-level dependency.
• Rebuild Gemfile.next.lock from Gemfile.lock with a conservative rails update, and pin the next
  constraint to ~> 8.0.0 so this step lands on Rails 8.0 (8.0.5.1) rather than 8.1.
• Drop :index from the singular contact resource. rails routes output is identical on 7.2
  before and after.

How it was tested (Docker: ruby:3.4.10 + postgres:16-alpine, same suites as the workflows):

Suite	Rails 8.0.5.1 (Gemfile.next)	Rails 7.2.3 (Gemfile)
models	783 examples, 0 failures	783 examples, 0 failures
controllers	542 examples, 0 failures	542 examples, 0 failures
ability	93 examples, 0 failures, 2 pending	93 examples, 0 failures, 2 pending
leftovers	95 examples, 0 failures, 1 pending	95 examples, 0 failures, 1 pending
features	106 examples, 0 failures, 3 pending	106 examples, 0 failures, 3 pending

Note: Rails 8.0 security support ends on 2026-11-07, so moving next to 8.1 would be a sensible
follow-up; happy to open that separately if useful.

[hennevogel]

Not sure how you ended up with 8.0.5 but pinning rails to ~> 8.0.0 will end up on 8.0.2 instead. And it looks like you mixed in some bundle update into it as there are many gem updates included. See #3843 and
https://github.com/fastruby/next_rails how to do this more cleanly...

Thanks for your contribution anyway!

[muhammadsamad99]

Thanks for taking this over in #3843, and for keeping me as co-author, much appreciated.

You're right about the lock. I copied Gemfile.lock to Gemfile.next.lock and then ran bundle update rails --conservative, which is where 8.0.5.1 and all the unrelated gem bumps came from. Bumping only factory_bot is the cleaner fix, and I'll follow the next_rails workflow you linked next time.

If it helps, I'm happy to do the Rails 8.1 step for the next bundle as a separate PR once #3843 is in, changing only rails and what it requires.