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
Gemfile(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)
bundle-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
bundle 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.
- •
- 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
programs 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
requirements 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
executables work
- •
- 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
version 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
Gemfile.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).