anchor.diff:  ENV HOSTNAME=${HOSTNAME_ARG}
   ENV MAXON_PORT=${MAXON_PORT_ARG}
   #VOLUME /licenses
  -VOLUME /sys/fs/cgroup
   EXPOSE ${MAXON_PORT}
   
  -ENV LM_LICENSE_FILE=/licenses
  +#ENV LM_LICENSE_FILE=/licenses
   ENV PATH=/opt/$UNAME/licenseserver/bin:${PATH}
   # add the maxon lib path to LD_LIBRARY_PATH
   ENV LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/opt/maxon/licenseserver/lib64
  
positive.code: 
  RUN yum update -y
  RUN yum clean all
  RUN yum install -y systemd redhat-lsb-core wget net-tools
  # clean up systemd, h/t https://serverfault.com/questions/824975/failed-to-get-d-bus-connection-operation-not-permitted
  RUN yum clean all; \
  (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == systemd-tmpfiles-setup.service ] || rm -f $i; done); \
  rm -f /lib/systemd/system/multi-user.target.wants/*; \
  rm -f /etc/systemd/system/*.wants/*; \
  rm -f /lib/systemd/system/local-fs.target.wants/*; \
  rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
  rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
  rm -f /lib/systemd/system/basic.target.wants/*; \
  rm -f /lib/systemd/system/anaconda.target.wants/*;
  RUN ls -lh /lib64/libstdc*
  #RUN ln -s 
  RUN rm -rf /var/cache/yum
  
  ENV RPM_URL=${RPM_URL_ARG}
  WORKDIR /tmp/$UNAME
  
negative.code: FROM centos/systemd
  LABEL maintainer="Alex Franks <alex-envoy@users.noreply.github.com>"
  
  # add this to build env in DockerHub if/when it changes
  