support multiple bundler versions

[modosc]

i've got this Appraisals:

appraise "rails-5.0" do
  gem "rails", "~> 5.0.0"
end

appraise "rails-5.1" do
  gem "rails", "~> 5.1.0"
end

appraise "rails-5.2" do
  gem "rails", "~> 5.2.0"
end

appraise "rails-6.0" do
  gem "rails", "~> 6.0.0"
end

appraise "rails-6.1" do
  gem "rails", "~> 6.1.0"
end

i tried to update it recently and discovered that there's a clash with bundler versions:

Note: Run `appraisal generate --travis` to generate Travis CI configuration.
true
>> bundle check --gemfile='/home/circleci/repo/gemfiles/rails_5.0.gemfile' || bundle install --gemfile='/home/circleci/repo/gemfiles/rails_5.0.gemfile' --retry 1
Bundler can't satisfy your Gemfile's dependencies.
Install missing gems with `bundle install`.
Fetching gem metadata from https://rubygems.org/..........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Bundler could not find compatible versions for gem "bundler":
  In rails_5.0.gemfile:
    bundler (~> 2.1.2)

    rails (~> 5.0.0) was resolved to 5.0.4, which depends on
      bundler (< 2.0, >= 1.3.0)

  Current Bundler version:
    bundler (2.1.2)
This Gemfile requires a different version of Bundler.
Perhaps you need to update Bundler by running `gem install bundler`?

is there a way to specify which bundler version is used for each appraise block? i added the version i needed but when the bundle install was called it still failed:

>> BUNDLE_GEMFILE=/Users/jon/git/cloudflare-rails/gemfiles/rails_5.0.gemfile bundle update
Fetching gem metadata from https://rubygems.org/..........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Bundler could not find compatible versions for gem "bundler":
  In rails_5.0.gemfile:
    bundler (~> 1.17.3)

  Current Bundler version:
    bundler (2.1.4)
This Gemfile requires a different version of Bundler.
Perhaps you need to update Bundler by running `gem install bundler`?

Could not find gem 'bundler (~> 1.17.3)' in any of the relevant sources:
  the local ruby installation

[nickcharlton]

Are you running the same bundler version as the one which is specified in the .lock file? I've seen that be a problem in the past. On CI I've had to specify it in the past when the container version and what we're using elsewhere differ.

[modosc]

no, that's the issue i'm trying to sort out. if i support rails 5 i'm forced to use bundler (~> 1.17.3) everywhere. i'm looking for a way to pass in the version number to appraisal so it uses it (eg, _2.1.4_ or whatever) in the bundle exec call it makes. does this make sense?

[nickcharlton]

Ah right, I see. I didn't find it necessary to use bundler ~> 1.17.3, but it did require some work for older Ruby versions.

Does this CircleCI config help at all? https://github.com/thoughtbot/administrate/blob/main/.circleci/config.yml

I ended up using an environment variable to set to bundler 2.1.4, so that we're using the same one for every Ruby version.

[pboling]

Hoping there will eventually be a way to have different bundler versions via Appraisal!

[pboling]

I was able to get it working!!

Working example of Appraisal & Combustion with a massive test matrix on Github Actions in my sanitize_email gem here: pboling/sanitize_email@a9c1d9a

• Ruby 2.3 - Ruby 3.3
• Rails 3.0 - Rails 7.1
• bundler 1 & bundler 2