$ bundle update [GEM] [--local] [--source=SOURCE]
--local: Do not attempt to fetch gems remotely and use
the gem cache instead
--source: Update a specific source (and all gems
associated with it)
Gemfile.lock. In general, you should use
bundle installto install the same exact gems and versions across machines. You would use
bundle updateto explicitly update the version of a gem.
$ bundle update
bundle updatewith no parameters, bundler will ignore any previously installed gems and resolve all dependencies again based on the latest versions of all gems available in the sources.
$ bundle update --source=SOURCE
:pathsource used in the
Gemfile. For instance, with a
http://github.com/rails/rails.git, you would call
bundle update --source rails.
Update all gems
If you run
bundle update with no parameters, bundler will
ignore any previously installed gems and resolve all dependencies again
based on the latest versions of all gems available in the sources.
Consider the following
source 'https://rubygems.org' gem 'rails', '3.0.0.rc' gem 'nokogiri'
When you run
bundle install the first time, bundler will
resolve all of the dependencies, all the way down, and install what you
Fetching source index for https://rubygems.org/ Installing rake (0.8.7) Installing abstract (1.0.0) Installing activesupport (3.0.0.rc) Installing builder (2.1.2) Installing i18n (0.4.1) Installing activemodel (3.0.0.rc) Installing erubis (2.6.6) Installing rack (1.2.1) Installing rack-mount (0.6.9) Installing rack-test (0.5.4) Installing tzinfo (0.3.22) Installing actionpack (3.0.0.rc) Installing mime-types (1.16) Installing polyglot (0.3.1) Installing treetop (1.4.8) Installing mail (2.2.5) Installing actionmailer (3.0.0.rc) Installing arel (0.4.0) Installing activerecord (3.0.0.rc) Installing activeresource (3.0.0.rc) Installing bundler (1.0.0.rc.3) Installing nokogiri (126.96.36.199) with native extensions Installing thor (0.14.0) Installing railties (3.0.0.rc) Installing rails (3.0.0.rc) Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.
As you can see, even though you have just two gems in the
Gemfile, your application actually needs 25 different gems
in order to run. Bundler remembers the exact versions it installed in
Gemfile.lock. The next time you run
bundle install, bundler skips the dependency resolution and
installs the same gems as it installed last time.
After checking in the
Gemfile.lock into version control and
cloning it on another machine, running
bundle install will
_still_ install the gems that you installed last time. You don't need to
worry that a new release of
However, from time to time, you might want to update the gems you are
using to the newest versions that still match the gems in your
To do this, run
bundle update, which will ignore the
Gemfile.lock, and resolve all the dependencies again. Keep
in mind that this process can result in a significantly different set
of the 25 gems, based on the requirements of new gems that the gem
authors released since the last time you ran
Update a list of gems.
Sometimes, you want to update a single gem in the
and leave the rest of the gems that you specified locked to the
versions in the
For instance, in the scenario above, imagine that
nokogiri releases version
1.4.4, and you want
to update it _without_ updating Rails and all of its dependencies. To
do this, run
bundle update nokogiri
Bundler will update
nokogiri and any of its dependencies,
but leave alone Rails and its dependencies.
Sometimes, multiple gems declared in your
satisfied by the same second-level dependency. For instance, consider the
source 'https://rubygems.org' gem 'thin' gem 'rack-perftools-profiler'
thin gem depends on
rack >= 1.0, while
rack-perftools-profiler depends on
rack ~> 1.0.
If you run bundle install, you get:
Fetching source index for https://rubygems.org/ Installing daemons (1.1.0) Installing eventmachine (0.12.10) with native extensions Installing open4 (1.0.1) Installing perftools.rb (0.4.7) with native extensions Installing rack (1.2.1) Installing rack-perftools_profiler (0.0.2) Installing thin (1.2.7) with native extensions Using bundler (1.0.0.rc.3)
In this case, the two gems have their own set of dependencies, but they
rack in common. If you run
thin, bundler will update
rack, which are dependencies
thin, but not
perftools.rb, which are dependencies of
rack-perftools_profiler. Note that
bundle update thin will update
rack even though
it's _also_ a dependency of
In short, when you update a gem using
bundle update, bundler will update all dependencies of that
gem, including those that are also dependencies of another gem.
In this scenario, updating the
thin version manually in the
Gemfile, and then running
bundle install will
eventmachine, but not