A bug is a crash or incorrect behavior. If you have a debugging or troubleshooting question, please open a discussion.

Environment

1. Ruby version: 3.2+ (tested on 3.3.7 and CI Ubuntu 22.04)
2. Rails version: 7.x
3. Shakapacker/Webpacker version: 8.x / 9.x
4. React on Rails version: master (16.2.0.rc.0)

Expected behavior

When running the install generator via bundle exec rails g react_on_rails:install, the generator's internal bundle add shakapacker command should operate on the target app's Gemfile, not inherit the parent process's Bundler context.

Actual behavior

The generator's system("bundle add shakapacker --strict") call (and other bundle commands) inherit BUNDLE_GEMFILE from the parent process. This causes:

1. In tests: The error appears repeatedly in CI logs:

   [!] There was an error parsing `injected gems`: You cannot specify the same gem twice with different version requirements.
   You specified: shakapacker (= 9.4.0) and shakapacker (>= 0). Gem already added.
    #  from .../dummy-for-generators/injected gems:1
   

2. In production: If a user runs the generator via bundle exec rails g react_on_rails:install from within another bundled context, the same conflict can occur.

Evidence in CI

This error appears in master CI runs, e.g.:

• https://github.com/shakacode/react_on_rails/actions/runs/20663192886

Search for "injected gems" in the logs to see multiple occurrences.

Root cause

In lib/generators/react_on_rails/install_generator.rb, lines 355, 366, and 373:

success = system("bundle add shakapacker --strict")  # line 355
bundle_success = system("bundle install")            # line 366
success = system("bundle exec rails shakapacker:install")  # line 373

These system() calls inherit the environment, including BUNDLE_GEMFILE which points to the outer project's Gemfile when running via bundle exec.

Proposed fix

Wrap bundle commands in Bundler.with_unbundled_env to isolate them:

success = Bundler.with_unbundled_env { system("bundle add shakapacker --strict") }

This pattern is already used elsewhere in the codebase:

• lib/react_on_rails/dev/process_manager.rb (lines 135-138)
• lib/react_on_rails/dev/pack_generator.rb (lines 178-181)
• rakelib/task_helpers.rb (lines 34-36, 89)

Small, reproducible repo

Not needed - reproducible in the main repo:

cd react_on_rails
bundle exec ruby -e "
  puts 'BUNDLE_GEMFILE inherited by child processes:'
  puts ENV['BUNDLE_GEMFILE']
  puts
  puts 'With Bundler.with_unbundled_env:'
  Bundler.with_unbundled_env { puts ENV['BUNDLE_GEMFILE'].inspect }
"

Output shows BUNDLE_GEMFILE points to outer project, but with_unbundled_env correctly clears it to nil.