BUNDLE-EXEC(1)BUNDLE-EXEC(1)NAMEbundle-exec - Execute a command in the context of the bundle
bundle exec command
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.
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.
bundle exec makes a number of changes to the shell environment, then
executes the command you specify in full.
· make sure that it´s still possible to shell out to bundle from
inside a command invoked by bundle exec (using $BUNDLE_BIN_PATH)
· put the directory containing executables (like rails, rspec,
rackup) for your bundle on $PATH
· make sure that if bundler is invoked in the subshell, it uses the
same Gemfile (by setting BUNDLE_GEMFILE)
· 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:
· disallow loading additional gems not in the bundle
· 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
· 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
· Override Gem.bin_path to use the gems in the bundle, making system
· Add all gems in the bundle into Gem.loaded_specs
When shelling out (using the system or backticks methods, for example),
Bundler´s environment changes will propagate to the subshell environ‐
ment. If you desire to shell out without Bundler´s environment changes,
simply employ the with_clean_env method. It will restore all environ‐
ment variables to what they were before Bundler was activated. For
`brew install wget`
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
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‐
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
March 2013 BUNDLE-EXEC(1)