anchor.diff:  
   FROM centos:8 AS centos8
   
  -RUN yum -y update && \
  +RUN set -x; yum -y update && \
       dnf -y install 'dnf-command(config-manager)' && \
       yum config-manager --set-enabled powertools && \
       yum -y install golang git systemd \
  
positive.code: # Use OpenSUSE Leap 42.3 to emulate SLES 12: https://en.opensuse.org/openSUSE:Build_Service_cross_distribution_howto#Detect_a_distribution_flavor_for_special_code
  FROM opensuse/leap:42.3 as sles12
  
  RUN zypper -n install git systemd autoconf automake flex libtool libcurl-devel libopenssl-devel libyajl-devel gcc gcc-c++ zlib-devel rpm-build expect cmake systemd-devel systemd-rpm-macros \
  # Add home:Ledest:devel repo to install >3.4 bison
  && zypper addrepo https://download.opensuse.org/repositories/home:Ledest:devel/openSUSE_Leap_42.3/home:Ledest:devel.repo \
  && zypper addrepo https://download.opensuse.org/repositories/devel:languages:go/openSUSE_Leap_42.3/devel:languages:go.repo \
  
negative.code: 
  FROM opensuse/leap:15.1 as sles15
  
  RUN set -x; zypper -n install git systemd autoconf automake flex libtool libcurl-devel libopenssl-devel libyajl-devel gcc gcc-c++ zlib-devel rpm-build expect cmake systemd-devel systemd-rpm-macros \
  # Add home:ptrommler:formal repo to install >3.4 bison
  && zypper addrepo https://download.opensuse.org/repositories/home:ptrommler:formal/openSUSE_Leap_15.1/home:ptrommler:formal.repo \
  && zypper addrepo https://download.opensuse.org/repositories/devel:languages:go/openSUSE_Leap_15.1/devel:languages:go.repo \
  