apache proxy undefined reference to `proxy_hook_scheme_handler'

出现这个错误时，我的编译参数为
./configure --prefix=/usr/local/apache2 --with-included-apr --enable-so --enable-deflate=shared --enable-expires=shared --enable-rewrite=shared --enable-static-support --disable-userdir  --enable-proxy-http


后来加上 --enable-proxy 就可以了
./configure --prefix=/usr/local/apache2 --with-included-apr --enable-so --enable-deflate=shared --enable-expires=shared --enable-rewrite=shared --enable-static-support --disable-userdir --enable-proxy  --enable-proxy-http