anchor.diff:          libwebp-dev                   \
           make"
   
  +# Do not require interaction during build
  +ARG DEBIAN_FRONTEND=noninteractive
  +
   # Bring build environment up to date and install build dependencies
  -RUN apt-get update                         && \
  -    apt-get install -y $BUILD_DEPENDENCIES && \
  +RUN apt-get update                                              && \
  +    apt-get install -t ${DEBIAN_RELEASE} -y $BUILD_DEPENDENCIES && \
       rm -rf /var/lib/apt/lists/*
   
   # Add configuration scripts
  
positive.code:         fonts-dejavu                  \
          xfonts-terminus"
  
  # Copy build artifacts into this stage
  COPY --from=builder ${PREFIX_DIR} ${PREFIX_DIR}
  
  # Bring runtime environment up to date and install runtime dependencies
  RUN apt-get update                                                                  && \
      apt-get install -y --no-install-recommends $RUNTIME_DEPENDENCIES                && \
      apt-get install -y --no-install-recommends $(cat "${PREFIX_DIR}"/DEPENDENCIES)  && \
      rm -rf /var/lib/apt/lists/*
  
  # Link FreeRDP plugins into proper path
  
negative.code: RUN ${PREFIX_DIR}/bin/build-guacd.sh "$BUILD_DIR" "$PREFIX_DIR"
  
  # Record the packages of all runtime library dependencies
  RUN ${PREFIX_DIR}/bin/list-dependencies.sh     \
          ${PREFIX_DIR}/sbin/guacd               \
          ${PREFIX_DIR}/lib/libguac-client-*.so  \
          ${PREFIX_DIR}/lib/freerdp2/*guac*.so   \
          > ${PREFIX_DIR}/DEPENDENCIES
  
  # Use same Debian as the base for the runtime image
  FROM debian:${DEBIAN_BASE_IMAGE}
  
  #
  # The Debian repository that should be preferred for dependencies (this will be
  # added to /etc/apt/sources.list if not already present)
  #
  # NOTE: Due to limitations of the Docker image build process, this value is
  # duplicated in an ARG in the first stage of the build.
  #
  ARG DEBIAN_RELEASE=buster-backports
  
  # Add repository for specified Debian release if not already present in
  # sources.list
  RUN grep " ${DEBIAN_RELEASE} " /etc/apt/sources.list || echo >> /etc/apt/sources.list \
      "deb http://deb.debian.org/debian ${DEBIAN_RELEASE} main contrib non-free"
  
  #
  # Base directory for installed build artifacts. See also the
  # CMD directive at the end of this build stage.
  #
  # NOTE: Due to limitations of the Docker image build process, this value is
  # duplicated in an ARG in the first stage of the build.
  #
  ARG PREFIX_DIR=/usr/local/guacamole
  
  