brew install or brew update 都很慢！
使用国内的镜像：
1、替换现有上游
git -C "$(brew --repo)" remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/brew.git
git -C "$(brew --repo homebrew/core)" remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/homebrew-core.git
git -C "$(brew --repo homebrew/cask)" remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/homebrew-cask.git
brew update
2、复原方法
git -C "$(brew --repo)" remote set-url origin https://github.com/Homebrew/brew.git
git -C "$(brew --repo homebrew/core)" remote set-url origin https://github.com/Homebrew/homebrew-core.git
git -C "$(brew --repo homebrew/cask)" remote set-url origin https://github.com/Homebrew/homebrew-cask.git
brew update
感觉还是家代理比较快：
临时添加代理：
export ALL_PROXY=socks5://127.0.0.1:1081
永久添加代理：
echo export ALL_PROXY=socks5://127.0.0.1:1080 >> ~/.bash_profile
source ~/.base_profile
