FreeBSD 中无法通过 ports 安装软件问题解决

在 FreeBSD 的 10.0 release 上面安装 nginx ，提示如下：

Ports Collection support for your FreeBSD version has ended, and no ports are guaranteed to build on this system. Please upgrade to a supported release.

No support will be provided if you silence this message by defining ALLOW_UNSUPPORTED_SYSTEM.

*** Error code 1

怎么解决呢？后来找到一个简单粗暴的方法：
生成一个新文件，如下：

# more /etc/make.conf
ALLOW_UNSUPPORTED_SYSTEM=YES

然后再 make install ，就 OK 了。