bundle-exec - bundler-1.9.9 Documentation

BUNDLE-EXEC(1) BUNDLE-EXEC(1)

NAME

    bundle-exec - Execute a command in the context of the bundle

SYNOPSIS

    bundle exec [--keep-file-descriptors] command

DESCRIPTION

    This  command  executes  the  command, making all gems specified in the
    Gemfile(5) available to require in Ruby programs.

    Essentially, if you  would  normally  have  run  something  like  rspec
    spec/my_spec.rb,  and  you  want  to use the gems specified in the Gem-
    file(5) and installed via bundle install(1) bundle-install.1.html,  you
    should run bundle exec rspec spec/my_spec.rb.

    Note  that bundle exec does not require that an executable is available
    on your shell's $PATH.

OPTIONS

    --keep-file-descriptors
           Exec in Ruby 2.0 began discarding non-standard file descriptors.
           When  this flag is passed, exec will revert to the 1.9 behaviour
           of passing all file descriptors to the new process.

BUNDLE INSTALL –BINSTUBS

    If  you  use  the   --binstubs   flag   in   bundle   install(1)   bun-
    dle-install.1.html,  Bundler  will  automatically  create  a  directory
    (which defaults to app_root/bin)  containing  all  of  the  executables
    available from gems in the bundle.

    After  using --binstubs, bin/rspec spec/my_spec.rb is identical to bun-
    dle exec rspec spec/my_spec.rb.

ENVIRONMENT MODIFICATIONS

        bundle exec makes a number of changes to the  shell  environment,  then
        executes the command you specify in full.

        o   make  sure  that  it's  still  possible to shell out to bundle from
            inside a command invoked by bundle exec (using $BUNDLE_BIN_PATH)

        o   put  the  directory  containing  executables  (like  rails,  rspec,
            rackup) for your bundle on $PATH

        o   make  sure  that if bundler is invoked in the subshell, it uses the
            same Gemfile (by setting BUNDLE_GEMFILE)

        o   add -rbundler/setup to $RUBYOPT, which makes sure  that  Ruby  pro-
            grams invoked in the subshell can see the gems in the bundle

        It also modifies Rubygems:

        o   disallow loading additional gems not in the bundle

        o   modify  the gem method to be a no-op if a gem matching the require-
            ments is in the bundle, and to raise a Gem::LoadError if it's not

        o   Define Gem.refresh to be a no-op, since the source index is  always
            frozen  when  using  bundler,  and  to prevent gems from the system
            leaking into the environment

        o   Override Gem.bin_path to use the gems in the bundle, making  system
            executables work

        o   Add all gems in the bundle into Gem.loaded_specs

    Shelling out
        Any  Ruby  code that opens a subshell (like system, backticks, or %x{})
        will automatically use the current Bundler environment. If you need  to
        shell  out  to  a Ruby command that is not part of your current bundle,
        use the with_clean_env method  with  a  block.  Any  subshells  created
        inside  the  block will be given the environment present before Bundler
        was activated. For example, Homebrew commands run Ruby, but don't  work
        inside a bundle:

            Bundler.with_clean_env do
              `brew install wget`
            end

        Using  with_clean_env  is  also  necessary if you are shelling out to a
        different bundle. Any Bundler commands run in a subshell  will  inherit
        the  current  Gemfile, so commands that need to run in the context of a
        different bundle also need to use with_clean_env.

            Bundler.with_clean_env do
              Dir.chdir "/other/bundler/project" do
                `bundle exec ./script`
              end
            end

        Bundler provides convenience helpers that wrap  system  and  exec,  and
        they can be used like this:

            Bundler.clean_system('brew install wget')
            Bundler.clean_exec('brew install wget')

RUBYGEMS PLUGINS

    At  present,  the  Rubygems  plugin  system  requires  all  files named
    rubygems_plugin.rb on the load path of any installed gem when any  Ruby
    code requires rubygems.rb. This includes executables installed into the
    system, like rails, rackup, and rspec.

    Since Rubygems plugins can contain arbitrary Ruby code,  they  commonly
    end up activating themselves or their dependencies.

    For  instance,  the gemcutter 0.5 gem depended on json_pure. If you had
    that version of gemcutter installed (even if you also had a newer  ver-
    sion  without  this problem), Rubygems would activate gemcutter 0.5 and
    json_pure <latest>.

    If your Gemfile(5) also contained json_pure (or a gem with a dependency
    on  json_pure),  the  latest version on your system might conflict with
    the version in your Gemfile(5), or the snapshot version  in  your  Gem-
    file.lock.

    If this happens, bundler will say:

        You have already activated json_pure 1.4.6 but your Gemfile
        requires json_pure 1.4.3. Consider using bundle exec.

    In  this  situation, you almost certainly want to remove the underlying
    gem with the problematic gem plugin. In general, the authors  of  these
    plugins  (in this case, the gemcutter gem) have released newer versions
    that are more careful in their plugins.

    You can find a list of all the gems containing gem plugins by running

        ruby -rubygems -e "puts Gem.find_files('rubygems_plugin.rb')"

    At the very least, you should remove all but the newest version of each
    gem  plugin, and also remove all gem plugins that you aren't using (gem
    uninstall gem_name).

                              December 2014                  BUNDLE-EXEC(1)