export LUAJIT_LIB=/usr/local/luajit/lib
export LUAJIT_INC=/usr/local/luajit/include/luajit-2.0
./configure --prefix=/application/nginx --with-ld-opt="-Wl,-rpath,$LUAJIT_LIB" --add-module=/usr/local/ngx_devel_kit --add-module /ngx_echo_module --with-debug

make -j2
make install

http://ntcn.net/blog/?p=4766