RVM is a command-line tool which allows you to easily install, manage, and work with multiple ruby environments from interpreters to sets of gems.
Use this instead of sudo gems!
Install RVM:
\curl -sSL https://get.rvm.io | bash -s stable
Quit and relaunch Terminal.
Check RVM version (1.29.7 or higher):
rvm -v
Ruby version (2.3.7 or higher):
ruby -v
Updating RVM:
rvm get stable
List known ruby versions:
rvm list known
Install a ruby version:
rvm install 2.6
See which ruby versions are installed:
rvm list rubies
Set default ruby:
rvm alias create default ruby-2.6.3
Make sure the RVM Ruby is used, not the OSX one:
which ruby
Should return something like /Users/skorset/.rvm/rubies/ruby-2.6.3/bin/ruby and not /usr/bin/ruby. If the latter is the case keep in mind that with MacOS Catalina the zsh is used rather than the bash, therefore, the ~/.zshrc needs to be configured instead of the .bash_profile.
List gemset:
rvm gemset list
Change gemset, e.g. to global:
rvm gemset use global
Use global cache for gems:
rvm gemset globalcache enable
List installed gems:
gem list
Install gems now for a single user (no sudo needed anymore):
gem install jazzy
Update Gems:
rvm gemset update
Cleanup:
rvm cleanup all