rbenv

fancy_echo "Installing rbenv, to change Ruby versions ..."
  brew_install_or_upgrade 'rbenv'

  if ! grep -qs "rbenv init" ~/.zshrc; then
    printf 'export PATH="$HOME/.rbenv/bin:$PATH"\n' >> ~/.zshrc
    printf 'eval "$(rbenv init - zsh --no-rehash)"\n' >> ~/.zshrc

    fancy_echo "Enable shims and autocompletion ..."
      eval "$(rbenv init - zsh)"
  fi

  export PATH="$HOME/.rbenv/bin:$PATH"

fancy_echo "Installing rbenv-gem-rehash so the shell automatically picks up binaries after installing gems with binaries..."
  brew_install_or_upgrade 'rbenv-gem-rehash'

fancy_echo "Installing ruby-build, to install Rubies ..."
  brew_install_or_upgrade 'ruby-build'