Homebrew 卸载时出现：Failed to locate Homebrew! 错误

今天在 MacBook 上安装 Homebrew，结果中间断了网，想重新卸载重装，结果一直卸载失败。问题现象如下：

问题现象

卸载时错误如下：

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"
Failed to locate Homebrew!

重装时错误如下：

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
It appears Homebrew is already installed. If your intent is to reinstall you
should do the following before running this installer again:
    ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"
The current contents of /usr/local are bin Cellar etc Frameworks Homebrew include lib opt sbin share var

问题分析

google 后发现有这样的问题讨论帖子，有人建议执行：

rm -rf /usr/local/.git

后再重新安装。貌似这个解决方案有很多人成功了。不过我这么做后还是出现卸载失败。

粗粗想了一下，大概因为是断网造成的，断网导致了安装不完全，在安装目录产生了一些不完整的目录文件。
查找了一下，找到一个目录
执行：

mdfind homebrew

找到：

/usr/local/Homebrew

cd 到/usr/local/目录，ls -al 了一下，发现还存在几个安装时出现过的目录名字，于是一并删除了。

下面是当初安装时的提示信息：

➜  local ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/share/doc/homebrew
/usr/local/share/man/man1/brew.1
/usr/local/share/zsh/site-functions/_brew
/usr/local/etc/bash_completion.d/brew
/usr/local/Homebrew
==> The following new directories will be created:
/usr/local/Cellar
/usr/local/Homebrew
/usr/local/Frameworks

Press RETURN to continue or any other key to abort

下面是 ls -al 的信息:

➜  local ls -al
total 0
drwxr-xr-x  13 Ade   wheel  442  9 12 19:15 .
drwxr-xr-x@ 12 root  wheel  408 12  5  2015 ..
drwxrwxr-x   2 Ade   admin   68  9 12 19:15 Cellar
drwxrwxr-x   2 Ade   admin   68  9 12 19:15 Frameworks
drwxrwxr-x   3 Ade   admin  102  9 12 19:15 Homebrew

问题解决

删除 Homebrew 安装时产生的目录

rm -rf Cellar Frameworks Homebrew

重新执行安装命令：

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

按照提示 回车 继续执行，
最后出现下面的提示表示安装成功

==> Installation successful!
==> Next steps
Run `brew help` to get started
Further documentation: https://git.io/brew-docs
==> Homebrew has enabled anonymous aggregate user behaviour analytics
Read the analytics documentation (and how to opt-out) here:
  https://git.io/brew-analytics

执行 brew help，正常显示命令帮助，Nice ！