py-qt5-xml does not currently install pre-compiled Python bytecode
which can cause build errors in poudriere for ports depending on it. If
the bytecode is not pre-installed, when the module is loaded Python creates
the bytecode on the fly causing the filesystem to be touched during the
build. For example:
http://package21.nyi.freebsd.org/data/111amd64-default-qat/463452/logs/errors/Carla-1.9.8.log