brew使用国内镜像源

# 步骤一
cd "$(brew --repo)"
git remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/brew.git

# 步骤二
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/homebrew-core.git

# 步骤三
brew update

注意这里需要等待一会，因为要更新资源。
更新完后使用brew update，brew install速度变快很多了，不会卡在那半天没动静，替换镜像完成。

复原

cd "$(brew --repo)"
git remote set-url origin https://github.com/Homebrew/brew.git
 
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://github.com/Homebrew/homebrew-core
 
brew update