Installation

How to get RubyGems and Bundler and keep them up to date.

RubyGems and Bundler ship with Ruby, so installing Ruby gives you both tools. To check that they are available:

gem --version
bundle --version

If you do not have Ruby yet, see the official installation guide for the options available on your platform.

Updating RubyGems

Ruby comes with the RubyGems version that was current when that Ruby was released. To upgrade to the latest version:

gem update --system

To upgrade to a specific version instead, pass the version number:

gem update --system <version>

Both forms download the rubygems-update gem and run its setup.rb, so they need network access. On a machine without it, fetch the release archive from the download page elsewhere, copy it over, then unpack it and install from the unpacked directory:

ruby setup.rb

Run ruby setup.rb --help for the available options.

Updating Bundler

To install the latest Bundler:

gem install bundler

Bundler is a default gem, so every Ruby installation always contains a version of it that cannot be uninstalled. Installing a newer version does not replace the default one. Both stay available.

Which Bundler version runs

A project’s Gemfile.lock records the Bundler version that created it under BUNDLED WITH. When you run bundle commands in that project, Bundler automatically switches to the recorded version if it is installed, even when a newer version is present. To update the recorded version to the latest installed Bundler, run bundle update --bundler. See Bundler compatibility for the Ruby and RubyGems versions each Bundler release supports.