The guide walks readers through installing Ruby on Ubuntu using three main approaches: system packages, rbenv, and RVM, and explains when each method is appropriate. It starts with a quick, package‑based install that hands you a stable Ruby version out of the box, then dives into rbenv for precise version control without touching system binaries, and finally covers RVM’s gemset management for projects that demand different environments. Throughout, the author shares real‑world anecdotes to illustrate common pitfalls like mismatched OpenSSL versions or accidentally mixing system gems with user‑managed ones, as well as tips on installing necessary build tools and libraries. By the end of the article, readers are equipped to choose the method that best fits their workflow and can avoid frequent headaches by following the outlined troubleshooting advice.

How to Install Ruby on Ubuntu

If you’re setting up a new project or just want to play around with Ruby, getting it installed on Ubuntu is a quick win. This guide will walk you through the most common paths—using the official packages, rbenv, and RVM—and explain why each choice matters.

1. Quick‑start with the default Ubuntu package

sudo apt update
sudo apt install ruby-full

ruby-full pulls a stable Ruby version (usually 2.6 or 2.7 on older releases) and its standard library, so you’re ready to run irb or any script right away. It’s the simplest route if you don’t need a newer release.

2. Installing a newer Ruby with rbenv

rbenv gives you fine‑grained control over which Ruby version is active without polluting the system packages.

1. Prerequisites

   sudo apt install git build-essential libssl-dev zlib1g-dev \
       libreadline-dev libyaml-dev libsqlite3-dev sqlite3

Those libraries let the Ruby source compile cleanly and add essential features like SSL and SQLite support.

2. Clone rbenv

   git clone https://github.com/rbenv/rbenv.git ~/.rbenv
   cd ~/.rbenv && src/configure && make -C src

Builds the runtime that manages Ruby binaries.

3. Add to your shell (for bash)

   echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
   echo 'eval "$(rbenv init -)"' >> ~/.bashrc
   source ~/.bashrc

Makes the rbenv command available immediately.

4. Install ruby-build plugin

   git clone https://github.com/rbenv/ruby-build.git \
       "$(rbenv root)/plugins/ruby-build"

Turns rbenv install into a one‑liner that fetches, compiles, and installs any Ruby version.

5. Pick a version

   rbenv install 3.2.2
   rbenv global 3.2.2

Sets 3.2.2 as the default for every shell session, ensuring your scripts run under that Ruby.

6. Verify

   ruby -v

You should see ruby 3.2.2p0.

3. Using RVM for flexibility (but with some baggage)

RVM installs Ruby into your home directory and manages gemsets. It’s handy if you frequently switch between projects that need different Ruby environments.

1. Install dependencies

   sudo apt install gnupg2 curl

2. Import GPG keys and install RVM

   gpg --keyserver hkp://pool.sks-keyservers.net --recv-keys \
       409B6B1796C275462A1703113804BB82D39DC0E3 \
       7D2BAF1CF37B13E2069D6956105BD0E739499BDB
   curl -sSL https://get.rvm.io | bash -s stable
   source ~/.rvm/scripts/rvm

The key import prevents tampering; the script installs RVM itself.

3. Install Ruby

   rvm install 2.7.6
   rvm use 2.7.6 --default

4. Verify

   ruby -v

4. Common pitfalls to avoid

• Mixing system Ruby and rbenv: If you install gems globally with sudo gem install, they’ll go under /usr/lib/ruby/gems/... and won’t be seen by the Ruby managed by rbenv or RVM. Stick to gem install --user-install unless you’re deliberately editing the system Ruby.
• Missing build tools: Forgetting build-essential or any of the SSL/SQLite libraries will leave you with a broken binary that refuses to run scripts. The error logs usually say “missing libssl” or “undefined symbol”.
• Old Ubuntu releases: On Ubuntu 18.04, ruby-full is 2.3, which is dead and insecure. If you’re on that distro, lean toward rbenv or RVM to get a newer version.