Homebrew

git -C "/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core" fetch --unshallow
brew update
brew doctor
brew cleanup

brew upgrade
brew upgrade --cask
brew doctor
brew cleanup

brew pin derby
brew list --pinned
brew unpin derby

brew list
brew list --cask
brew deps --tree --installed

brew services list
brew services run derby
brew services stop derby
brew services start derby
brew services restart derby

export PATH="/usr/local/opt/ruby/bin:$PATH"

RBEnv

brew install rbenv
rbenv init
:'
# Load rbenv automatically by appending
# the following to ~/.bash_profile:

eval "$(rbenv init -)"
'

curl -fsSL https://github.com/rbenv/rbenv-installer/raw/master/bin/rbenv-doctor | bash
:'
Checking for `rbenv' in PATH: /usr/local/bin/rbenv
Checking for rbenv shims in PATH: OK
Checking `rbenv install' support: /usr/local/bin/rbenv-install (ruby-build 20201118)
Counting installed Ruby versions: none
  There aren't any Ruby versions installed under `/Users/shahed/.rbenv/versions'.
  You can install Ruby versions like so: rbenv install 2.2.4
Checking RubyGems settings: OK
Auditing installed plugins: OK
'

echo "gem: no-document" > ~/.gemrc 
brew upgrade rbenv ruby-build
rbenv install --list
rbenv install 2.7.2
rbenv global 2.7.2

Cocoapods

gem install cocoapods
#eval "$(rbenv init -)"
export LANG=en_US.UTF-8
pod --version

References

• Groom your app’s Ruby environment with rbenv
• CocoaPods working on MacOS Big Sur