[libvirt] Why using AC_PATH_PROG to detect the location of run-time external programs

Hello, I am wondering why AC_PATH_PROG is used to detect the location of run-time external programs (such as dnsmasq, ovs-vsctl, etc.), and hardcoded the locations in binary. It seems wrong to me. At compile-time, configure script should only determine whether the resulting binary should support the use of these external programs. The actual location of these programs should be determined at run-time, either from libvirtd.conf or by $PATH. I haven't looked into how to fix it. The problem I ran into earlier is this: on my dev box, I have Open vSwitch utility ovs-vsctl installed locally in /usr/local/bin. Therefore, at build-time, libvirt detected the location of ovs-vsctl and hardcoded '/usr/local/bin/ovs-vsctl' in libvirtd. When I package libvirt and install it on my test box, it couldn't find ovs-vsctl, as ovs-vsctl is installed at /usr/bin/ovs-vsctl in the test box, so it failed. Thanks, Howard