Mac中更新安装gcc报错：Error: The following directories are not writable by your user

前几天为Mac搭建gcc的环境，在使用指令

brew install gcc

报错：

Error: **The following directories are not writable by your user:
/usr/local/share/doc
/usr/local/share/man
/usr/local/share/man/man1

You should change the ownership of these directories to your user.
  sudo chown -R $(whoami) /usr/local/share/doc /usr/local/share/man /usr/local/share/man/man1

And make sure that your user has write permission.
  chmod u+w /usr/local/share/doc /usr/local/share/man /usr/local/share/man/man1

大概长这样
出现这种情况是Mac里权限的问题
继续在终端输入：

sudo chown -R `whoami`:admin /usr/local/bin

sudo chown -R `whoami`:admin /usr/local/share

因为使用了sudo，可能会提示需要输入密码，直接输入Mac密码就行

然后就可以正常更新安装了
中间有一段下载速度慢，需要耐心等待

祝你好运！！！