Homebrewでgraphvizをインストールしようとしたら以下のようなエラーが表示された．
==> Downloading from https://akamai.bintray.com/a1/a1283e332d0754e450a7e46a1e1b0 ######################################################################## 100.0% ==> Pouring python-3.7.4_1.mojave.bottle.tar.gz Error: An unexpected error occurred during the `brew link` step The formula built, but is not symlinked into /usr/local Permission denied @ dir_s_mkdir - /usr/local/Frameworks/Python.framework Error: Permission denied @ dir_s_mkdir - /usr/local/Frameworks/Python.framework
解決策を知りたいときはbrew doctorコマンドを打つと解決策を教えてくれる．すごい便利．
$ 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: The following directories do not exist: /usr/local/sbin You should create these directories and change their ownership to your account. sudo mkdir -p /usr/local/sbin sudo chown -R $(whoami) /usr/local/sbin
というわけで，/usr/local/sbinディレクトリを作って設定を変えたらちゃんとインストールできた．
