Rebuild against xen 4.12.
DEBUG util.py:554: BUILDSTDERR: - conflicting requests
DEBUG util.py:554: BUILDSTDERR: - nothing provides libxenctrl.so.4.11()(64bit) needed by qemu-system-x86-core-2:4.0.0-0.5.rc2.fc31.x86_64
DEBUG util.py:554: BUILDSTDERR: - nothing provides libxenguest.so.4.11()(64bit) needed by qemu-system-x86-core-2:4.0.0-0.5.rc2.fc31.x86_64