Bundler 0.9 to 1.0 and above

Upgrading from Bundler 0.9 to 1.0 is relatively painless. The Gemfile API is the same, so your old Gemfiles should continue to work.

The "env" file that 0.9 created at .bundle/environment.rb has been removed. As a side effect of this, Passenger will only find your bundled gems if you install with bundle install --deployment. Alternatively, you can tell Passenger where you gems are installed, something like this.

The bundle lock command is no longer needed, as the Gemfile.lock file is now automatically generated by bundle install. If you have not yet done so, add your Gemfile.lock to source control and check it in.

Running bundle install no longer updates the versions of your gems. If you need to update just one gem, run bundle update GEMNAME. To update all gems to the newest versions possible, run bundle update.

Bundler now supports multiple platforms, using a block syntax to declare platform-specific gems:

platform :jruby do
  gem "jruby-maven-plugins"
end

Deploying using Bundler is even easier than it was before, as Bundler now includes a Capistrano recipe. Simply add this line to the top of your deploy.rb file to run Bundler automatically as part of deploying:

require 'bundler/capistrano'

For more details on deploying using bundler, see the documentation for the bundler cap task, and the documentation on deploying.

Bundler 0.8 to 0.9 and above

Upgrading to Bundler 0.9 from Bundler 0.8 requires upgrading several API calls in your Gemfile, and some workarounds if you are using Rails 2.3.

Gemfile Removals

Bundler 0.9 removes the following Bundler 0.8 Gemfile APIs:

1. disable_system_gems: This is now the default (and only) option for bundler. Bundler uses the system gems you have specified in the Gemfile, and only the system gems you have specified (and their dependencies)
2. disable_rubygems: This is no longer supported. We are looking into ways to get the fastest performance out of each supported scenario, and we will make speed the default where possible.
3. clear_sources: Bundler now defaults to an empty source list. If you want to include Rubygems, you can add the source via source "http://gemcutter.org". If you use bundle init, this source will be automatically added for you in the generated Gemfile
4. bundle_path: You can specify this setting when installing via bundle install /path/to/bundle. Bundler will remember where you installed the dependencies to on a particular machine for future installs, loads, setups, etc.
5. bin_path: Bundler no longer generates executables in the root of your app. You should use bundle exec to execute executables in the current context.

Gemfile Changes

Bundler 0.9 changes the following Bundler 0.8 Gemfile APIs:

1. Bundler 0.8 supported :only and :except as APIs for describing groups of gems. Bundler 0.9 supports a single group method, which you can use to group gems together. See the above "Group" section for more information.

   This means that gem "foo", :only => :production becomes gem "foo", :group => :production, and only :production { gem "foo" } becomes group :production { gem "foo" }

   The short version is: group your gems together logically, and use the available commands to make use of the groups you've created.

2. :require_as becomes :require

3. :vendored_at is fully removed; you should use :path

API Changes

1. Bundler.require_env(:environment) becomes Bundler.require(:multiple, :groups). You must now specify the default group (the default group is the group made up of the gems not assigned to any group) explicitly. So Bundler.require_env(:test) becomes Bundler.require(:default, :test)

2. require 'vendor/gems/environment': In unlocked mode, where using system gems, this becomes Bundler.setup(:multiple, :groups). If you don't specify any groups, this puts all groups on the load path. In locked mode, it becomes require '.bundle/environment'