anchor.diff:  RUN sed -i s/jessie/trusty/g /etc/apt/sources.list.d/hvr-ghc-jessie.list
   RUN apt-get update
   RUN apt-get install -y cabal-install-1.22 ghc-7.8.4 happy-1.19.4 alex-3.1.3 && apt-get clean
  -ENV PATH /opt/cabal/1.22/bin:/opt/ghc/7.8.4/bin:/opt/happy/1.19.4/bin:/opt/alex/3.1.3/bin:$PATH
  +ENV PATH /home/jovyan/.cabal/bin:/opt/cabal/1.22/bin:/opt/ghc/7.8.4/bin:/opt/happy/1.19.4/bin:/opt/alex/3.1.3/bin:$PATH
   
   # IHaskell dependencies
   RUN apt-get install -y --no-install-recommends zlib1g-dev libzmq3-dev libtinfo-dev libcairo2-dev libpango1.0-dev && apt-get clean
  
positive.code: ENV HOME /home/jovyan
  ENV SHELL /bin/bash
  ENV USER jovyan
  ENV PATH $CONDA_DIR/bin:$PATH
  WORKDIR $HOME
  
  USER jovyan
  
negative.code: RUN julia -e 'Pkg.add("Gadfly")' && julia -e 'Pkg.add("RDatasets")'
  
  # IHaskell
  RUN cabal update && \
      cabal install cpphs && \
      cabal install gtk2hs-buildtools && \
  