Problem Autoconf dengan PHP

Versi FreeBSD 8.1-RELEASE
Versi Autoconf 2.68
Versi PHP  5.3.3_2

Problem saat penambahan extension PHP:

Cannot find autoconf. Please check your autoconf installation and the $PHP_AUTOCONF environment variable is set correctly and then rerun this script.

server# export PHP_AUTOCONF="/usr/local/bin/autoconf"

Cannot find autoconf. Please check your autoconf installation and the $PHP_AUTOHEADER environment variable is set correctly and then rerun this script.

server# export PHP_AUTOHEADER="/usr/local/bin/autoheader"

Jalankan 2 perintah diatas saat mendapatkan masalah tersebut.