anchor.diff:  # Build guacamole-server from local source
   RUN /opt/guacd/bin/build-guacd.sh "$BUILD_DIR" "$PREFIX_DIR"
   
  -# Use same CentOS as the base for the runtime image
  -FROM centos:${CENTOS_VERSION}
  +# Use same Ubuntu as the base for the runtime image
  +FROM ubuntu:${UBUNTU_VERSION}
   
   # Base directory for installed build artifacts.
   # Due to limitations of the Docker image build process, this value is
  
positive.code: ARG BUILD_DEPENDENCIES="              \
          autoconf                      \
          automake                      \
          cairo-devel                   \
          freerdp-devel                 \
          gcc                           \
          libjpeg-turbo-devel           \
          libssh2-devel                 \
          libtool                       \
          libtelnet-devel               \
          libvorbis-devel               \
          libvncserver-devel            \
          libwebp-devel                 \
          make                          \
          pango-devel                   \
          pulseaudio-libs-devel         \
          uuid-devel"
  
  # Build time environment
  ENV LC_ALL=en_US.UTF-8
  
  # Bring build environment up to date and install build dependencies
  RUN yum -y update                        && \
      yum -y install epel-release          && \
      yum -y install $BUILD_DEPENDENCIES   && \
      yum clean all
  
  # Add configuration scripts
  COPY src/guacd-docker/bin /opt/guacd/bin/
  
negative.code: #
  
  
  # Use Ubuntu as base for the build
  ARG UBUNTU_VERSION=xenial
  FROM ubuntu:${UBUNTU_VERSION} AS builder
  
  # Base directory for installed build artifacts.
  # Due to limitations of the Docker image build process, this value is
  