anchor.diff:  # Install R packages
   # Our pre-built R packages from rspm are built against system libs in focal
   # rstan takes forever to compile from source, and needs libnodejs
  -# We don't want R 4.1 yet - the graphics protocol version it has is incompatible
  -# with the version of RStudio we use. So we pin R to 4.0.5
  -# Our pre-built R packages from rspm are built against system libs in focal
  -# rstan takes forever to compile from source, and needs libnodejs
   # So we install older (10.x) nodejs from apt rather than newer from conda
  -ENV R_VERSION=4.0.5-1.2004.0
  +ENV R_VERSION=4.1.2-1.2004.0
   RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
   RUN echo "deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/" > /etc/apt/sources.list.d/cran.list
   RUN apt-get update -qq --yes > /dev/null && \
       apt-get install --yes -qq \
       r-base-core=${R_VERSION} \
       r-base-dev=${R_VERSION} \
  -    r-cran-littler=0.3.11-1.2004.0 \
  +    r-cran-littler=0.3.14-1.2004.0 \
       libglpk-dev \
       libzmq5 \
       nodejs npm > /dev/null
  
positive.code: 
  #install rsession proxy
  RUN pip install --no-cache-dir \
          jupyter-rsession-proxy==1.2
  
  # Install IRKernel
  RUN r -e "install.packages('IRkernel', version='1.1.1')" && \
      r -e "IRkernel::installspec(prefix='${CONDA_DIR}')"
  
  # Install R packages, cleanup temp package download location
  
negative.code:         lsb-release \
          libclang-dev  > /dev/null
  
  ENV RSTUDIO_URL https://download2.rstudio.org/server/bionic/amd64/rstudio-server-2021.09.1-372-amd64.deb
  RUN curl --silent --location --fail ${RSTUDIO_URL} > /tmp/rstudio.deb && \
      dpkg -i /tmp/rstudio.deb && \
      rm /tmp/rstudio.deb
  