Can't install php-gtk-0.5.2 correctly for pptp-php-gtk-20030

[linuxbug]

I want to install pptp-php-gtk-20030505 on my gentoo system.So I have to install php-gtk-0.5.2 first.But When I install it,the following error was occur:


checking for PHP extension directory... /usr/lib/php4
checking for PHP-GTK support... yes, shared
checking for gawk... gawk
checking for PHP executable in /usr/bin... found
./configure: line 2606: syntax error near unexpected token `debug,'
./configure: line 2606: `PHP_GTK_ARG_ENABLE(debug, whether to include debugging symbols,'
[root@php-gtk-0.5.2 ]

who can tell me how to install php-gtk-0.5.2?