bundler-explain

This project aims to give better explanations conflicts on bundle install.

Consider this Gemfile:

gem 'rails', '~> 5.0.0'
gem 'quiet_assets'

Running bundle update we get this error:

Bundler could not find compatible versions for gem "rails":
  In Gemfile:
    rails (~> 5.0.0)

Could not find gem 'rails (~> 5.0.0)' in any of the sources.

Bundler could not find compatible versions for gem "railties":
  In Gemfile:
    quiet_assets was resolved to 1.0.1, which depends on
      railties (~> 3.1)

    rails (~> 5.0.0) was resolved to 5.0.0, which depends on
      railties (= 5.0.0)

bundler has tried every version of quiet_assets and rails, and found that none are compatible. However it's a little unclear from this.

Bundler can only report one of the many failed combinations it has tried (here rails 5.0.0 and quiet_assets 1.0.1, neither of which the most recent version).

bundler-explain aims to show the user why there are no possible solutions:

Because quiet_assets 1.0.1 depends on railties ~> 3.1
  and quiet_assets <= 1.0.0 depends on rails ~> 3.1,
  quiet_assets <= 1.0.0 OR 1.0.1 requires railties ~> 3.1 or rails ~> 3.1.
And because quiet_assets >= 1.0.2 depends on railties < 5.0, >= 3.1,
  either railties < 5.0, >= 3.1 or rails ~> 3.1.
So, because rails >= 5.0.0, <= 5.0.7 depends on railties ~> 5.0.0
  and root depends on rails ~> 5.0.0,
  version solving has failed.

With more gems, bundler's output will be more verbose but bundler-explain will only describe relevant gems. See a more complex example.

bundler-explain uses PubGrub to determine the cause of the failure.

$ gem i pub_grub # Needs to be installed first
$ bundler plugin install bundler-explain

This will install the bundler-explain plugin and bundle update will now use bundler-explain's error messages.

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 tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/jhawthorn/bundler-explain. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

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

Everyone interacting in the Bundler::Explain project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.