112 lines
4.1 KiB
Markdown
112 lines
4.1 KiB
Markdown
bundle-exec(1) -- Execute a command in the context of the bundle
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================================================================
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## SYNOPSIS
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`bundle exec` <command>
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## DESCRIPTION
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This command executes the command, making all gems specified in the
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`Gemfile(5)` available to `require` in Ruby programs.
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Essentially, if you would normally have run something like
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`rspec spec/my_spec.rb`, and you want to use the gems specified
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in the `Gemfile(5)` and installed via [bundle install(1)][bundle-install], you
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should run `bundle exec rspec spec/my_spec.rb`.
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Note that `bundle exec` does not require that an executable is
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available on your shell's `$PATH`.
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## BUNDLE INSTALL --BINSTUBS
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If you use the `--binstubs` flag in [bundle install(1)][bundle-install], Bundler will
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automatically create a directory (which defaults to `app_root/bin`)
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containing all of the executables available from gems in the bundle.
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After using `--binstubs`, `bin/rspec spec/my_spec.rb` is identical
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to `bundle exec rspec spec/my_spec.rb`.
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## ENVIRONMENT MODIFICATIONS
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`bundle exec` makes a number of changes to the shell environment,
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then executes the command you specify in full.
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* make sure that it's still possible to shell out to `bundle`
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from inside a command invoked by `bundle exec` (using
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`$BUNDLE_BIN_PATH`)
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* put the directory containing executables (like `rails`, `rspec`,
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`rackup`) for your bundle on `$PATH`
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* make sure that if bundler is invoked in the subshell, it uses
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the same `Gemfile` (by setting `BUNDLE_GEMFILE`)
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* add `-rbundler/setup` to `$RUBYOPT`, which makes sure that
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Ruby programs invoked in the subshell can see the gems in
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the bundle
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It also modifies Rubygems:
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* disallow loading additional gems not in the bundle
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* modify the `gem` method to be a no-op if a gem matching
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the requirements is in the bundle, and to raise a
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`Gem::LoadError` if it's not
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* Define `Gem.refresh` to be a no-op, since the source
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index is always frozen when using bundler, and to
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prevent gems from the system leaking into the environment
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* Override `Gem.bin_path` to use the gems in the bundle,
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making system executables work
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* Add all gems in the bundle into Gem.loaded_specs
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### Shelling out
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When shelling out (using the `system` or backticks methods,
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for example), Bundler's environment changes will propogate to
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the subshell environment. If you desire to shell out without
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Bundler's environment changes, simply employ the `with_clean_env`
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method. It will restore all environment variables to what they
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were before Bundler was activated. For example:
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Bundler.with_clean_env do
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`brew install wget`
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end
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## RUBYGEMS PLUGINS
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At present, the Rubygems plugin system requires all files
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named `rubygems_plugin.rb` on the load path of _any_ installed
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gem when any Ruby code requires `rubygems.rb`. This includes
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executables installed into the system, like `rails`, `rackup`,
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and `rspec`.
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Since Rubygems plugins can contain arbitrary Ruby code, they
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commonly end up activating themselves or their dependencies.
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For instance, the `gemcutter 0.5` gem depended on `json_pure`.
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If you had that version of gemcutter installed (even if
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you _also_ had a newer version without this problem), Rubygems
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would activate `gemcutter 0.5` and `json_pure <latest>`.
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If your Gemfile(5) also contained `json_pure` (or a gem
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with a dependency on `json_pure`), the latest version on
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your system might conflict with the version in your
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Gemfile(5), or the snapshot version in your `Gemfile.lock`.
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If this happens, bundler will say:
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You have already activated json_pure 1.4.6 but your Gemfile
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requires json_pure 1.4.3. Consider using bundle exec.
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In this situation, you almost certainly want to remove the
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underlying gem with the problematic gem plugin. In general,
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the authors of these plugins (in this case, the `gemcutter`
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gem) have released newer versions that are more careful in
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their plugins.
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You can find a list of all the gems containing gem plugins
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by running
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ruby -rubygems -e "puts Gem.find_files('rubygems_plugin.rb')"
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At the very least, you should remove all but the newest
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version of each gem plugin, and also remove all gem plugins
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that you aren't using (`gem uninstall gem_name`).
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