The requested PHP extension ext-mcrypt * is missing from your system と言われた時の解決方法

composerのinstallでエラーがでました。環境はMacOSX10.10.5です。

composerのinstallでエラー

php composer.phar install
Loading composer repositories with package information
Installing dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - The requested PHP extension ext-mcrypt * is missing from your system

ext-mcryptがないようです。

php -v
PHP 5.6.4 (cli) (built: Jan  7 2015 01:04:24) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2014 Zend Technologies

brewでPHPを入れていたと思うのでbrewで入れます。

brew install php56-mcrypt

再度composer install

php composer.phar install

今度は成功しました(^o^)