一、通过homebrew查看是否有异常（首先你得安装了Homebrew）
$ brew doctor
二、根据提示修改zsh配置
Warning: Homebrew's sbin was not found in your PATH but you have installed
formulae that put executables in /usr/local/sbin.
Consider setting the PATH for example like so:
echo 'export PATH="/usr/local/sbin:$PATH"' >> ~/.zshrc
三、实际操作
$ vim ~/.zshrc
将 export PATH="/usr/local/sbin:$PATH 添加到配置文件中
$ source ~/.zshrc
$ which git
$ git --version
四、如果还是不行只需要手动下载git-gui即可
$ brew install git-gui