Bundler Why

A Bundler plugin that shows why a specific package is installed in your Ruby project, similar to yarn why in Yarn/npm.

This gem is a Bundler plugin that helps you understand the dependency tree of your gems and why a particular gem is required by your project.

Install this plugin by running:

bundle plugin install bundler-why-plugin

To install from a local path during development:

bundle plugin install bundler-why-plugin --source /path/to/bundler-why-plugin

To see why a specific package is installed:

bundle why <package_name>

❯ bundle why ffi
ffi (1.17.3)

Directly required by:
  ├── libddwaf (1.30.0.0.0) [~> 1.0]
  │     └── datadog (2.26.0) [~> 1.30.0.0.0]
  └── rb-inotify (0.11.1) [~> 1.0]
        └── listen (3.10.0) [~> 0.9, >= 0.9.10]

Location: /Users/hsbt/.local/share/gem/specifications/ffi-1.17.3-arm64-darwin.gemspec

The bundle why command performs the following:

1. Parses your Gemfile.lock: Loads the current bundle configuration
2. Analyzes dependencies: Traces which gems depend on the specified package
3. Displays results: Shows:
   • The gem's version number
   • Direct dependents (gems that directly require it)
   • All dependents (both direct and indirect)
   • The gem's installation location

• Shows direct dependents of a package
• Traces the full dependency chain
• Displays gem versions and requirement specifiers
• Handles both direct and transitive dependencies
• Clear, Yarn-like output format

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/hsbt/bundler-why-plugin.

The gem is available as open source under the terms of the MIT License.