anchor.diff:  COPY install_redis.sh /tmp/build/
   RUN /tmp/build/install_redis.sh
   
  -# Install Emacs 24.5 from private Debian package
  +# Install Emacs 26.1 from private Debian package
   # to work around https://github.com/docker/docker/issues/22801
   
  -# RUN wget http://ftp.gnu.org/gnu/emacs/emacs-24.5.tar.gz && tar xzf emacs-24.5.tar.gz
  -# WORKDIR /tmp/build/emacs-24.5
  -# RUN ./configure && make && make install
  +# RUN wget http://ftp.gnu.org/gnu/emacs/emacs-26.1.tar.gz && tar xzf emacs-26.1.tar.gz
  +# WORKDIR /tmp/build/emacs-26.1
  +# RUN ./configure --with-gnutls=no && make && make install
  +#
  +# To build private Debian package:
  +# See https://github.com/jordansissel/fpm/wiki/PackageMakeInstall
  +#
  +# Install Ruby and FPM
  +# make install DESTDIR=/tmp/installdir
  +# fpm -s dir -t deb -C /tmp/installdir -n emacs26.1 -v 26.1-1 \
  +#     -p emacs26.1_VERSION_ARCH.deb --description 'Emacs 26.1' usr
   
  -RUN wget https://s3-us-west-1.amazonaws.com/royseto-public/dpkg/emacs24.5.2_24.5.2-1_amd64.deb \
  -  && dpkg -i /tmp/build/emacs24.5.2_24.5.2-1_amd64.deb
  +RUN wget https://s3-us-west-1.amazonaws.com/royseto-public/dpkg/emacs26.1_26.1-1_amd64.deb \
  +  && dpkg -i /tmp/build/emacs26.1_26.1-1_amd64.deb
   
   # Install Python 2.7.11.
   
  
positive.code: # Add package repositories.
  
  RUN apt-get install -y -q software-properties-common && \
      add-apt-repository 'deb http://cran.rstudio.com/bin/linux/ubuntu xenial/' && \
      add-apt-repository -y ppa:git-core/ppa && \
      add-apt-repository -y ppa:pi-rho/dev && \
      apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E084DAB9 && \
  
negative.code: 
  RUN pip install csvkit
  
  # Install PhantomJS.
  
  COPY install_phantomjs.sh /tmp/build/
  