brew update ,Error: /usr/local is not writable. You should change the ownership 解決方法
ターミナルで$brew update ができなかったので、メモ 答え書いてあるけど
$ brew update Error: /usr/local is not writable. You should change the ownership and permissions of /usr/local back to your user account: sudo chown -R $(whoami) /usr/local
$sudo chown -R $(whoami) /usr/local
こちらでpermissionを変更してあげれば解決です