HomevbrewでFormulaを更新しようとしたら「Error: SHA1 mismatch」が発生して更新出来なかったのでその時の対処法。

$ brew upgrade
==> Upgrading 1 outdated package, with result:
ricty 3.2.2
==> Upgrading ricty
==> Downloading https://github.com/yascentur/Ricty/archive/3.2.2.tar.gz
Already downloaded: /Library/Caches/Homebrew/ricty-3.2.2.tar.gz
==> Downloading http://levien.com/type/myfonts/Inconsolata.otf
Already downloaded: /Library/Caches/Homebrew/Inconsolata.otf
==> Downloading http://sourceforge.jp/frs/redir.php?m=iij&f=%2Fmix-mplus-ipa%2F59022%2Fmigu-1m-20130617.zip
Already downloaded: /Library/Caches/Homebrew/redir.php
Error: SHA1 mismatch
Expected: a0641894cec593f8bb1e5c2bf630f20ee9746b18
Actual: 5fb8634d4f67df3889e98c1491e9d6b335bc95c7
Archive: /Library/Caches/Homebrew/redir.php
(To retry an incomplete download, remove the file above.)

一旦ダウンロード済みのファイルをCachesディレクトリから削除。

$ rm /Library/Caches/Homebrew/Inconsolata.otf /Library/Caches/Homebrew/ricty-3.2.2.tar.gz /Library/Caches/Homebrew/redir.php

念のためHomebrewを最新にする。

$ brew update

再度upgradeで成功。

$ brew upgrade