How can you preview the updates that a "Bundle Update" will make?

Question

Sometimes I want to run bundle update but only to see which gems need updating. I don't necessarily want to deal with the issues associated with updating all of them but I want to do a quick check to see what's the state of the art.

Is there a way to simply get Bundler to list the gems that need to be updated together (ideally) with the version I'm currently running and what's the latest and greatest?

Answer 1

I tried this:

> gem install bundle_outdated
> bundle-outdated
Finding outdated gems..

Newer versions found for:
  rails (3.1.0 > 3.0.0)
  haml (3.1.2 > 3.0.0)
  rspec-rails (2.6.1 > 2.0.1)

Lock bundle to these versions by putting the following in your Gemfile:
  gem 'rails', '3.1.0'
  gem 'haml', '3.1.2'
  gem 'rspec-rails', '2.6.1'

You may try to update non-specific dependencies via:
  $ bundle update haml rspec-rails

Handwaving specifications:
  haml: >= 3.0.0
  rspec-rails: >= 2.0.1

Another alternative:

> gem install gem-outdated
> gem outdated