Installing Elixir and Erlang With ASDF

Many programming languages regularly release new versions that add or deprecate features, fix bugs, and introduce breaking changes. To help developers switch between versions easily, several language communities have version managers (like NVM for Node.js or Rbenv for Ruby). When you need to switch versions of multiple languages at once, however, the ASDF version manager ensures each project has the environment it needs.

This is especially important in Elixir projects, which require the Erlang runtime. In this guide, you'll learn how to install specific versions of Elixir and Erlang/OTP using the ASDF version manager on macOS or Linux.

The ASDF version manager is a command-line tool that is available on GitHub. It uses curl and git to install various languages.

To install the curl and git utilities, run:

You can learn more about Homebrew on macOS here.

With the prerequisites installed, now clone the ASDF project:

If you ever wish to remove ASDF, you can do so by removing .asdf from your home directory and undo the configuration changes described below.

Finally, include ASDF in your shell's configuration. For zsh, add the following to ~/.zshrc:

Alternatively, if you use oh-my-zsh, add asdf to your plugin configuration. To include ASDF in your configuration when using a different shell, consult the documentation.

ASDF uses a plugin system to support multiple languages. For a typical Elixir project, you will need the Elixir and Erlang plugins:

If your project requires Node.js, you can also install the nodejs plugin.

With ASDF and its plugins installed, you can now install Elixir and Erlang. If your project has a .tool-versions file with entries for elixir and erlang, you can install the correct versions by running the following from inside the project:

The .tool-versions file is much like .nvmrc and .ruby-version files, except that it lists the names and versions of multiple languages. In general, the names in this file should match the names of the language's plugin (e.g. nodejs for Node.js).

If you do not yet have a .tool-versions file, or want to install Elixir and Erlang globally, use the following to see a list of all available Erlang/OTP versions:

Unlike other version managers, ASDF requires you to specify a precise version of the language to install. To install version 23.2.1 of Erlang, run:

Warning: This installation will take some time while it compiles Erlang from source.

Erlang will compile modules based on the available libraries from your system. For example, some features (such as the built-in observer) require wx libraries. You may see messages during the installation about omitted modules, which will not affect the rest of the runtime.

Once the Erlang runtime is installed, you are ready to install Elixir. To see a list of all available versions, run:

Notice that each Elixir release has multiple versions compiled with different major versions of Erlang/OTP. To maximize compatibility between Elixir and the Erlang runtime, choose a -otp-XY version that matches the major version of the runtime you installed in the previous step. For example:

Installing Elixir takes significantly less time than installing Erlang/OTP.

Now that you have Elixir and Erlang/OTP installed, you can save your chosen versions in a project. From the root of the project, run:

Replace the versions above with those you used during installation. This will create a .tool-versions file in your project, which will instruct ASDF which versions to use. If you'd like to set a global, or default, version, run:

This will create a .tool-versions file in your home directory. ASDF will use these versions whenever a project doesn't specify versions of its own.

ASDF is a popular version manager for Elixir projects because it manages both Elixir and Erlang versions. Include a .tool-versions file in your projects to help contributors get up-and-running quickly, and don't forget to leverage the -otp-XY versions of Elixir for the best compatibility.

If you'd like to learn more about Elixir and what it can do for your next project, check out Elixir: The Big Picture here on Pluralsight.