I had the same issue using zsh and this fixed it:

Copy$ echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.zshenv
$ echo 'eval "$(rbenv init -)"' >> ~/.zshenv
$ echo 'source $HOME/.zshenv' >> ~/.zshrc
$ exec $SHELL

Try the following:

sudo apt-get install rubygems

I did confirm that the rubocop executable is in /usr/local/lib/ruby/gems/2.7.0/bin. Do I need to add this directory to $PATH?

Yes, the bin directory needs to be in your path. A little trick I use to keep the current version's directory in the PATH is something like this in .bashrc (or .zshrc whatever it is for you)

export PATH="$PATH:$(ruby -e 'puts Gem.user_dir')/bin"

check your rc files

• .zshenv
• .zshrc
• .zlogin
• .zprofile

most likely in one of those PATH is reset after RVM was sourced

also some oh-my-zsh plugins can break stuff, try disabling them and enabling one by one.

Thanks to historystamp's comment here is how the problem was solved (for bash shell):

1. Open/Launch Terminal
2. gem uninstall iStats (source)
3. gem install iStats --user-install (source)
4. export PATH="~/.gem/ruby/2.6.0/bin:$PATH" (source)
5. source ~/.bash_profile (source)
6. istats

If you use macOS Catalina, the default shell is zsh. The adapted instructions are the following:

1. Open/Launch Terminal
2. gem uninstall iStats (source)
3. gem install iStats --user-install (source)
4. Open or create ~/.zshrc
5. At the end of the file (or where appropriate) insert: export PATH=~/.gem/ruby/2.6.0/bin:$PATH (source)
6. Save file ~/.zshrc
7. Source the .zshrc file: . ~/.zshrc (source)
8. istats

It's evident that you've managed to mess up your PATH variable. (Your current PATH doesn't contain any location where common utilities are located.)

Try:

PATH=/bin:/usr/bin:/usr/local/bin:/sbin:${PATH}
export PATH

Alternatively, for "resetting" zsh, specify the complete path to the shell:

exec /bin/zsh

or

exec /usr/bin/zsh

Your $PATH variable needs to include the exact path to your Ruby's bin directory. Adding a directory to the PATH does not include it's subfolders. Try adding the bin directory via:

export PATH=$PATH:/home/adam/.gem/ruby/1.8/bin

or if you installed the gem using sudo:

export PATH=$PATH:/usr/lib/ruby/gems/1.8/bin

You might want to add this to your .bashrc file, so that you don't have to set this manually every time your open up a new bash.

Homebrew is nice. However unlike brew and npm, gem does not make aliases in /usr/local/bin automatically.

Solution

I went for a very simple approach (updated December 2025):

# https://stackoverflow.com/a/14138490/319266
# Based on "`brew --prefix ruby`/bin"
export PATH="/opt/homebrew/opt/ruby/bin:$PATH"
# Based on "`gem environment gemdir`/bin"
export PATH="/opt/homebrew/lib/ruby/gems/3.3.0/bin:$PATH"

Add this to your .bashrc (or .bash_profile, .zshrc, etc.).

That's it! Now all Ruby bins and installed gems will be available from your shell!

In older versions of Homebrew (before 2017), there was a separate package for Ruby 2 called ruby20, for which you'd use the following snippet instead:

export PATH=/usr/local/opt/ruby20/bin:$PATH

This line was the only line needed at the time. But, in Ruby 2.1 the gems got moved to a separate directory. No longer under /usr/local/opt/ruby/bin, but instead at /usr/local/lib/ruby/gems/2.0.0/bin (where "2.0.0" is the last major Ruby version for Gem's purposes).

How it works

Homebrew keeps track of where it installed a package, and maintains a symbolic link for you that points there.

# Mac Intel
$ brew --prefix ruby
/usr/local/opt/ruby

# Apple Silicon (M-series)
$ brew --prefix ruby
/opt/homebrew/opt/ruby

$ l /usr/local/opt/ruby
/usr/local/opt/ruby@ -> ../Cellar/ruby/3.3.4

Effectively, adding /opt/homebrew/opt/ruby/bin to PATH is the same as the following:

export PATH=/opt/homebrew/Cellar/ruby/3.3.4/bin:$PATH

Except, this expanded path would hardcode the currently installed version of Ruby and would stop working next time you upgrade Ruby.

As for Gem, the following command will tell you the exact directory Gem adds new packages to:

# Example as of 2019
$ gem environment gemdir
/usr/local/lib/ruby/gems/2.7.0

# Example as of 2025
$ gem environment gemdir
/opt/homebrew/lib/ruby/gems/3.3.0

Tools

These tools were meant to automatically bridge between Homebrew and Gem:

• josh/brew-gem (no longer exists)
• indirect/brewbygems (unmaintained)

I haven't used these but they might work for you.

Question:

➜ ~ mvn

zsh: command not found: mvn

Answer:

step 1:

vim ~/.zshrc

step 2:(Add at the end of the file)

source ~/.bash_profile;

step 3:(Execution shell)

> source ~/.bash_profile

You can use mvn :

➜  / mvn

[INFO] Scanning for projects...
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