macOS brew `require': cannot load such file -- active_support/core_ext/object/blank (LoadError) 错误

刚刚使用 brew cleanup 命令清理了下 brew，然后再次运行 brew 就出现了如下的错误

/usr/local/Homebrew/Library/Homebrew/global.rb:12:in `require': cannot load such file -- active_support/core_ext/object/blank (LoadError)
    from /usr/local/Homebrew/Library/Homebrew/global.rb:12:in `<top (required)>'
    from /usr/local/Homebrew/Library/Homebrew/brew.rb:23:in `require_relative'
    from /usr/local/Homebrew/Library/Homebrew/brew.rb:23:in `<main>'

好吧，清理命令把 brew 自己搞坏了。修复方法很简单，就一条命令

brew update-reset