[libvirt] Hard requirement on gcrypt.h?

Hi, I'm building libvirt for the first time and figuring out what libraries are required to get the simplest possible thing working. Is there a hard requirement on gcrypt? I got libvirt past the configure script but the build failed on gcrypt.h. It looks like the include for it could be moved inside the #if WITH_GNUTLS section of libirt.c, if I understand what configure.ac is trying to set up. Thoughts? Thanks! Eugene