何の気なしに表題を実施した。

■ 環境

• Homebrew
• macOS High Sierra

■ brew doctor

$ brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: You have unlinked kegs in your Cellar
Leaving kegs unlinked can lead to build-trouble and cause brews that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  google-cloud-sdk

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"' >> ~/.bash_profile

Warning: Broken symlinks were found. Remove them with `brew prune`:
  /usr/local/bin/chef-zero
  /usr/local/bin/docker-credential-osxkeychain.backup
  /usr/local/bin/fauxhai
  /usr/local/bin/hyperkit.backup
  /usr/local/bin/notary.backup
  /usr/local/bin/vpnkit.backup
$

3点ほど問題があるらしい。

■ Warning: You have unlinked kegs in your Cellar

“google-cloud-sdk“に対しての問題のようだ。`brew link`を実施してみるもエラーとなる。

$ brew link google-cloud-sdk
Error: Multiple kegs installed to /usr/local/Cellar/google-cloud-sdk
However we don't know which one you refer to.
Please delete (with rm -rf!) all but one and then try again.
$

使用していないし削除しようかと思い下記を実施。

$ brew uninstall google-cloud-sdk
Error: Multiple kegs installed to /usr/local/Cellar/google-cloud-sdk
However we don't know which one you refer to.
Please delete (with rm -rf!) all but one and then try again.
$

特に変化なし。削除してしまう。

$ rm -rf /usr/local/Cellar/google-cloud-sdk

■ Warning: Homebrew’s sbin was not found in your PATH but you have installed

“/usr/local/sbin“に対するPATHが足りないようである。自身の環境では”.bashrc“にいろいろ記載しているのでこちらに追記するようにした。

$ echo 'export PATH="/usr/local/sbin:$PATH"' >> ~/.bashrc

実際にはコマンドで追記ではなく直接編集した。

■ Warning: Broken symlinks were found. Remove them with `brew prune`:

不要なシンボリックリンクが残ってしまっているようだ。記載された通りに実施。

$ brew prune
Pruned 6 symbolic links and 8 directories from /usr/local
$

これらの対応で問題が無くなったようである。

$ brew doctor
Your system is ready to brew.
$

以上。