BUNDLE-UPDATE(1)					      BUNDLE-UPDATE(1)



NAME
       bundle-update - Update your gems to the latest available versions

SYNOPSIS
       bundle update *gems [--source=NAME]

DESCRIPTION
       Update  the  gems specified (all gems, if none are specified), ignoring
       the previously installed gems specified in the  Gemfile.lock.  In  gen-
       eral, you should use bundle install(1) bundle-install.1.html to install
       the same exact gems and versions across machines.

       You would use bundle update to explicitly update the version of a  gem.

OPTIONS
       --source=<name>
	      The  name  of a :git or :path source used in the Gemfile(5). For
	      instance,       with	 a	  :git	      source	    of
	      http://github.com/rails/rails.git,  you would call bundle update
	      --source rails

UPDATING 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 Gemfile(5):



	   source "http://rubygems.org"

	   gem "rails", "3.0.0.rc"
	   gem "nokogiri"



       When you run bundle install(1) bundle-install.1.html  the  first  time,
       bundler	will  resolve  all  of the dependencies, all the way down, and
       install what you need:



	   Fetching source index for http://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 (1.4.3.1) 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(5),
       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(1) bundle-install.1.html, 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(1)  bundle-install.1.html
       will  still  install  the  gems that you installed last time. You don't
       need to worry that a new release of erubis or mail changes the gems you
       use.

       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  Gem-
       file(5).

       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 bundle update.

UPDATING A LIST OF GEMS
       Sometimes, you want to update a single gem in the Gemfile(5), and leave
       the rest of the gems that you specified locked to the versions  in  the
       Gemfile.lock.

       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.

OVERLAPPING DEPENDENCIES
       Sometimes, multiple gems declared in your Gemfile(5) are  satisfied  by
       the  same  second-level	dependency. For instance, consider the case of
       thin and rack-perftools-profiler.



	   source "http://rubygems.org"

	   gem "thin"
	   gem "rack-perftools-profiler"



       The 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 http://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
       share rack in common. If you  run  bundle  update  thin,  bundler  will
       update  daemons, eventmachine and rack, which are dependencies of thin,
       but  not   open4   or   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 rack-perftools_profiler.

       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(5),
       and  then  running  bundle  install(1)  bundle-install.1.html will only
       update daemons and eventmachine, but not rack.  For  more  information,
       see  the  CONSERVATIVE  UPDATING  section  of  bundle  install(1)  bun-
       dle-install.1.html.

RECOMMENDED WORKFLOW
       In general, when working with an application managed with bundler,  you
       should use the following workflow:

       o   After you create your Gemfile(5) for the first time, run

	   $ bundle install

       o   Check the resulting Gemfile.lock into version control

	   $ git add Gemfile.lock

       o   When  checking  out this repository on another development machine,
	   run

	   $ bundle install

       o   When checking out this repository on a deployment machine, run

	   $ bundle install --deployment

       o   After changing the Gemfile(5) to reflect a  new  or	update	depen-
	   dency, run

	   $ bundle install

       o   Make sure to check the updated Gemfile.lock into version control

	   $ git add Gemfile.lock

       o   If bundle install(1) bundle-install.1.html reports a conflict, man-
	   ually update the specific gems that you changed in the Gemfile(5)

	   $ bundle update rails thin

       o   If you want to update all the gems to the latest possible  versions
	   that still match the gems listed in the Gemfile(5), run

	   $ bundle update






				 October 2010		      BUNDLE-UPDATE(1)
