Update:

• With one command , I have a-paid script that will create a Ruby environment.

• Also, I updated my guide. It explains how to install Ruby gems on a Mac. I recommend only using chruby or ruby-install.

MacOS will not allow you to modify the Ruby version that came with your Mac. It is possible to install gems such as bundler with a different version of Ruby than the one supplied by Apple.

sudo is not recommended for installing gems or changing permissions on system files and directories. This applies even if you are a skilled programmer. We need to stop giving this poor advice. This article explains why sudo should not be used to install gems.

Two main steps are required to find the solution:

1. Install a different version of Ruby to ensure that it does not conflict with the one you have.
2. Make sure your PATH is updated so that the new Ruby version’s location is the first in the PATH. This is done automatically by some tools. You should be familiar with PATH to understand how it works. This will help you understand why you get ” command failed to find” errors, as well as how you can fix them.

There are many ways to install Ruby on Mac. The best method that I recommend and which I wish was more common in the various installation guides out there is to use an automated script such as Ruby for Mac, which will create a proper Ruby environment.

It saves everyone a lot of time. Our most precious and limited resource is time. It is a waste of time to make things manual when you can automate them with perfect results every time.

It also drastically reduces human error and errors due to incomplete instructions.

Continue reading if you prefer to do it manually. You will first need to install . This installs the required command line tools and makes it easy for you to install any other tools.

These are the easiest ways to install Ruby in a different version.

You can switch between multiple Ruby versions easily [RECOMMENDED]

Select one of the following options:

• chruby, ruby install are my personal recommendations. These are the ones that are automatically installed using the Ruby for Mac script. These can be installed using Homebrew

brew install chruby ruby-install

• Benv can be installed using Homebrew

• 
  RVM

• 
  asdf

You can install Ruby as follows if you choose chruby or ruby-install.

ruby-install ruby

After you have installed everything and set up your .zshrc/.bash_profile according the instructions, close Terminal and restart it. Then, switch to the Ruby version you prefer. It would look something like this for chruby:

chruby 3.1.0

Which shell are you using will determine whether you need to set up .zshrc or .bash_profile.

You can be certain that you don’t require more than one Ruby version at once (other than the one that comes with macOS).

Even if you don’t think you’ll need it now, eventually you will and you won’t be able switch easily. This can cause confusion and headaches.

• Homebrew allows you to install ruby

brew install ruby

Next, run this command to update your PATH

echo 'export PATH="/usr/local/opt/ruby/bin:/usr/local/lib/ruby/gems/2.7.0/bin:$PATH"' >> ~/.zshrc

The 2.7.0 command assumes Homebrew has installed a Ruby version starting with 2.7. You can use ruby -v to check if you are using a different version.

Next, “refresh” the shell to allow these changes take effect.

source ~/.zshrc

You can also open a new tab in Terminal, quit Terminal and start it again.

If you’re using Bash, replace .zshrc by .bash_profile You can read my guide to determine which shell is being used.

You can use the following commands to verify that you are using the non-system Ruby version:

which ruby

It should not be /usr/bin/ruby

ruby -v

If you are using macOS Catalina or Monterey, it should be at least 2.6.3. 3.1.0 is the most recent Ruby version as of early 2022.

After you have installed this version of Ruby, you can install bundler (or any other gem).

gem install bundler