mac osのbrew install がうまくいかない

気がついたらbrew installがうまくいかなくなっていたので調べてみました。
OSversion: 10.13.6

以下実行とエラー

$ brew install libsub pkg-config

touch: /usr/local/Homebrew/.git/FETCH_HEAD: Permission denied
touch: /usr/local/Homebrew/Library/Taps/caskroom/homebrew-cask/.git/FETCH_HEAD: Permission denied
touch: /usr/local/Homebrew/Library/Taps/caskroom/homebrew-versions/.git/FETCH_HEAD: Permission denied
touch: /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/.git/FETCH_HEAD: Permission denied
touch: /usr/local/Homebrew/Library/Taps/homebrew/homebrew-services/.git/FETCH_HEAD: Permission denied
touch: /usr/local/Homebrew/Library/Taps/homebrew/homebrew-versions/.git/FETCH_HEAD: Permission denied
fatal: Unable to create '/usr/local/Homebrew/.git/index.lock': Permission denied
error: could not lock config file .git/config: Permission denied
Error: No available formula with the name "libsub"

解決方法

sudo chown -R $(whoami) $(brew --prefix)/*