Seamlessly manage your app’s Ruby environment with rbenv.
rbenv is a version manager tool for the Ruby programming language on Unix-like systems. It is useful for switching between multiple Ruby versions on the same machine and for ensuring that each project you are working on always runs on the correct Ruby version.
How It Works
After rbenv injects itself into your PATH at installation time, any invocation of
bundler, or other Ruby-related executable will first activate rbenv. Then, rbenv scans the current project directory for a file named
.ruby-version. If found, that file determines the version of Ruby that should be used within that directory. Finally, rbenv looks up that Ruby version among those installed under
You can choose the Ruby version for your project with, for example:
cd myproject # choose Ruby version 3.1.2: rbenv local 3.1.2
Doing so will create or update the
.ruby-version file in the current directory with the version that you've chosen. A different project of yours that is another directory might be using a different version of Ruby altogether—rbenv will seamlessly transition from one Ruby version to another when you switch projects.
Finally, almost every aspect of rbenv's mechanism is customizable via plugins written in bash.
The simplicity of rbenv has its benefits, but also some downsides. See the comparison of version managers for more details and some alternatives.
On systems with Homebrew package manager, the “Using Package Managers” method is recommended. On other systems, “Basic Git Checkout” might be the easiest way of ensuring that you are always installing the latest version of rbenv.
Using Package Managers
Install rbenv using one of the following approaches.
On macOS or Linux, we recommend installing rbenv with Homebrew.
brew install rbenv ruby-build
Debian, Ubuntu, and their derivatives
Note that the version of rbenv that is packaged and maintained in the Debian and Ubuntu repositories is out of date. To install the latest version, it is recommended to install rbenv using git.
sudo apt install rbenv
Arch Linux and its derivatives
Archlinux has an AUR Package for rbenv and you can install it from the AUR using the instructions from this wiki page.
Learn how to load rbenv in your shell.
# run this and follow the printed instructions: rbenv init
Close your Terminal window and open a new one so your changes take effect.
That's it! You are now ready to install some Ruby versions.
Basic Git Checkout
For a more automated install, you can use rbenv-installer. If you do not want to execute scripts downloaded from a web URL or simply prefer a manual approach, follow the steps below.
This will get you going with the latest version of rbenv without needing a system-wide install.
Clone rbenv into
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
Configure your shell to load rbenv:
Ubuntu Desktop users should configure
echo 'eval "$(~/.rbenv/bin/rbenv init - bash)"' >> ~/.bashrc
On other platforms, bash is usually configured via
echo 'eval "$(~/.rbenv/bin/rbenv init - bash)"' >> ~/.bash_profile
echo 'eval "$(~/.rbenv/bin/rbenv init - zsh)"' >> ~/.zshrc
For Fish shell:
echo 'status --is-interactive; and ~/.rbenv/bin/rbenv init - fish | source' >> ~/.config/fish/config.fish
If you are curious, see here to understand what
Restart your shell so that these changes take effect. (Opening a new terminal tab will usually do it.)
Installing Ruby versions
rbenv install command does not ship with rbenv out-of-the-box, but is provided by the ruby-build plugin.
Before attempting to install Ruby, check that your build environment has the necessary tools and libraries. Then:
# list latest stable versions: rbenv install -l # list all local versions: rbenv install -L # install a Ruby version: rbenv install 3.1.2
BUILD FAILED scenarios, check the ruby-build Discussions section.
rbenv installcommand wasn't found, you can install ruby-build as a plugin:git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build
Set a Ruby version to finish installation and start using Ruby:
rbenv global 3.1.2 # set the default Ruby version for this machine # or: rbenv local 3.1.2 # set the Ruby version for this directory
Alternatively to the
rbenv install command, you can download and compile Ruby manually as a subdirectory of
~/.rbenv/versions. An entry in that directory can also be a symlink to a Ruby version installed elsewhere on the filesystem.
Installing Ruby gems
Select a Ruby version for your project using
rbenv local 3.1.2, for example. Then, proceed to install gems as you normally would:
gem install bundler
You should not use sudo to install gems. Typically, the Ruby versions will be installed under your home directory and thus writeable by your user. If you get the “you don't have write permissions” error when installing gems, it's likely that your "system" Ruby version is still a global default. Change that with
rbenv global <version>and try again.
Check the location where gems are being installed with
gem env home # => ~/.rbenv/versions/<version>/lib/ruby/gems/...
Uninstalling Ruby versions
As time goes on, Ruby versions you install will accumulate in your
To remove old Ruby versions, simply
rm -rf the directory of the
version you want to remove. You can find the directory of a particular
Ruby version with the
rbenv prefix command, e.g.
rbenv prefix 2.7.0.
The ruby-build plugin provides an
rbenv uninstall command to
automate the removal process.
The main rbenv commands you need to know are:
Lists all Ruby versions known to rbenv, and shows an asterisk next to the currently active version.
$ rbenv versions 1.8.7-p352 1.9.2-p290 * 1.9.3-p327 (set by /Users/sam/.rbenv/version) jruby-1.7.1 rbx-1.2.4 ree-1.8.7-2011.03
Displays the currently active Ruby version, along with information on how it was set.
$ rbenv version 1.9.3-p327 (set by /Users/sam/.rbenv/version)
Sets a local application-specific Ruby version by writing the version
name to a
.ruby-version file in the current directory. This version
overrides the global version, and can be overridden itself by setting
RBENV_VERSION environment variable or with the
rbenv local 3.1.2
When run without a version number,
rbenv local reports the currently
configured local version. You can also unset the local version:
rbenv local --unset
Sets the global version of Ruby to be used in all shells by writing
the version name to the
~/.rbenv/version file. This version can be
overridden by an application-specific
.ruby-version file, or by
RBENV_VERSION environment variable.
rbenv global 3.1.2
The special version name
system tells rbenv to use the system Ruby
(detected by searching your
When run without a version number,
rbenv global reports the
currently configured global version.
Sets a shell-specific Ruby version by setting the
environment variable in your shell. This version overrides
application-specific versions and the global version.
rbenv shell jruby-1.7.1
When run without a version number,
rbenv shell reports the current
RBENV_VERSION. You can also unset the shell version:
rbenv shell --unset
Note that you'll need rbenv's shell integration enabled (step 3 of
the installation instructions) in order to use this command. If you
prefer not to use shell integration, you may simply set the
RBENV_VERSION variable yourself:
Installs shims for all Ruby executables known to rbenv (
~/.rbenv/versions/*/bin/*). Typically you do not need to run this command, as it will run automatically after installing gems.
Displays the full path to the executable that rbenv will invoke when you run the given command.
$ rbenv which irb /Users/sam/.rbenv/versions/1.9.3-p327/bin/irb
Lists all Ruby versions that contain the specified executable name.
$ rbenv whence rackup 1.9.3-p327 jruby-1.7.1 ree-1.8.7-2011.03
You can affect how rbenv operates with the following settings:
||Specifies the Ruby version to be used.
||Defines the directory under which Ruby versions and shims reside.
||Outputs debug information.
||see wiki||Colon-separated list of paths searched for rbenv hooks.|
||Directory to start searching for
How rbenv hooks into your shell
rbenv init is a helper command to bootstrap rbenv into a shell. This helper is part of the recommended installation instructions, but optional, as an advanced user can set up the following tasks manually. Here is what the command does when its output is
rbenvexecutable to PATH if necessary.
~/.rbenv/shimsdirectory to PATH. This is basically the only requirement for rbenv to function properly.
Installs shell completion for rbenv commands.
Regenerates rbenv shims. If this step slows down your shell startup, you can invoke
rbenv init -with the
Installs the "sh" dispatcher. This bit is also optional, but allows rbenv and plugins to change variables in your current shell, making commands like
You can run
rbenv init - for yourself to inspect the generated script.
The simplicity of rbenv makes it easy to temporarily disable it, or uninstall from the system.
To disable rbenv managing your Ruby versions, simply comment or remove the
rbenv initline from your shell startup configuration. This will remove rbenv shims directory from PATH, and future invocations like
rubywill execute the system Ruby version, bypassing rbenv completely.
rbenvwill still be accessible on the command line, but your Ruby apps won't be affected by version switching.
To completely uninstall rbenv, perform step (1) and then remove the rbenv root directory. This will delete all Ruby versions that were installed under
rm -rf "$(rbenv root)"
If you've installed rbenv using a package manager, as a final step perform the rbenv package removal:
brew uninstall rbenv
- Debian, Ubuntu, and their derivatives:
sudo apt purge rbenv
- Archlinux and its derivatives:
sudo pacman -R rbenv
Tests are executed using Bats:
$ bats test $ bats test/<file>.bats
Please feel free to submit pull requests and file bugs on the issue tracker.