anchor.diff:    && chmod a+x /usr/local/bin/php-cs-fixer \
     && cd /
   
  -# Set up tools for Python code generation; these are:
  -#   pandoc: an apt package that can convert text between formats
  -#     (example: Markdown to Restructured Text)
  -#   protoc-docs-plugin: A protoc plugin to add docstrings to the Python
  -#     protoc output.
  -RUN apt-get update \
  -  && apt-get install -y pandoc \
  -  && pip3 install protoc-docs-plugin==0.3.0 \
  -  && rm -rf /var/lib/apt/lists/*
  -
  -# Install .NET Core SDK (about 280MB)
  -# Install .NET CLI dependencies
  -RUN apt-get update \
  -    && apt-get install -y --no-install-recommends \
  -    libc6 \
  -    libcurl3 \
  -    libgcc1 \
  -    libgssapi-krb5-2 \
  -    liblttng-ust0 \
  -    libssl1.0.0 \
  -    libstdc++6 \
  -    libunwind8 \
  -    libuuid1 \
  -    zlib1g \
  -    && rm -rf /var/lib/apt/lists/*
  +# Used to add docstrings to the Python protoc output.
  +RUN pip3 install protoc-docs-plugin==0.3.0
   
   # Install .NET Core SDK
   ENV DOTNET_SDK_VERSION 1.0.4
  
positive.code: ENV LANGUAGE en_US:en
  ENV LC_ALL C
  
  # Install essential packages.
  RUN apt-get update \
    && apt-get install -y --no-install-recommends \
      build-essential \
      man-db \
      pkg-config \
      libffi-dev \
      libssl-dev \
      curl \
      kdiff3 \
      git \
      vim \
      less \
      openssh-client \
    && rm -rf /var/lib/apt/lists/*
  
  # Install runtime packages.
  RUN apt-get update \
    && apt-get install -y \
      unzip \
      perl \
      software-properties-common \
      php-pear \
      python3-pip \
    && rm -rf /var/lib/apt/lists/*
  
  # Install protoc 3.6.0.
  
negative.code:   && gem install grpc-tools --version '=1.10.0' --no-ri --no-rdoc
  
  # Install grpc_php_plugin
  RUN git clone -b v1.7.2 --recurse-submodules https://github.com/grpc/grpc.git /temp/grpc \
    && cd /temp/grpc \
    && make -j $(nproc) grpc_php_plugin \
    && mv ./bins/opt/grpc_php_plugin /usr/local/bin/ \
    && cd / \
  