macOS Sierra へのアップグレード

MacBook Pro Retina, Mid 2012 の Mavericks を Sierra へアップグレードしたときのメモ

Homebrew

brew update で

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

というエラーが出るので，言われるままに

$ sudo chown -R $(whoami) /usr/local

アップデート後

Homebrew no longer needs to have ownership of /usr/local. If you wish you can
return /usr/local to its default ownership with:
  sudo chown root:wheel /usr/local

と言われるので，言われるままに

$ sudo chown root:wheel /usr/local