/usr/bin/phpize
Configuring for:
PHP Api Version: 20121113
Zend Module Api No: 20121212
Zend Extension Api No: 220121212
Cannot find autoconf. Please check your autoconf installation and the
$PHP_AUTOCONF environment variable. Then, rerun this script.

解决办法也简单，在终端中运行如下命令：

$ brew install autoconf

如果 Homebrew 未安装，可先参考：Homebrew 套件管理器使 Mac OS X 更完美

$ ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"