Ports方式安装php5-extensions的gd模块出错

在一台freebsd服务器上安装Apache+PHP+MySQL时，在用Ports方式安装php5-extensions时碰到一个问题，提示如下错误：

===> Patching for php5-gd-5.2.3
===> Applying FreeBSD patches for php5-gd-5.2.3
===> php5-gd-5.2.3 depends on executable in : phpize - found
===> php5-gd-5.2.3 depends on file: /usr/local/bin/autoconf259 - found
===> php5-gd-5.2.3 depends on file: /usr/local/libdata/xorg/libraries - not found
===> Verifying install for /usr/local/libdata/xorg/libraries in /usr/ports/x11/xorg-libraries
/usr/X11R6 exists, but it is not a symlink. Installation cannot proceed.
This looks like an incompletely removed old version of X. In the current version, /usr/X11R6 must be a symlink if it exists at all.Please read /usr/ports/UPDATING (entry of 20070519) for the procedure to upgrade X.org related ports.
*** Error code 1Stop in /usr/ports/x11/xorg-libraries.
*** Error code 1

Stop in /usr/ports/graphics/php5-gd.
*** Error code 1

Stop in /usr/ports/lang/php5-extensions.
*** Error code 1

Stop in /usr/ports/lang/php5-extensions.

要修复这个问题，我只需要在make install clean的时候添加WITHOUT_X11=yes参数即可！