anchor.diff:  FROM ubuntu:xenial as nodejs_tools_context
   
   ENV NODEJS_VERSION=12.8.0
  +ENV MARKDOWN_SPELLCHECK_VERSION=v1.3.1
  +ENV SASS_LINT_VERSION=v1.13.1
  +ENV TYPESCRIPT_VERSION=v3.5.3
  +ENV TSLINT_VERSION=v5.18.0
  +ENV SASS_VERSION=v1.22.10
  +ENV SVGO_VERSION=v1.3.0
  +ENV SVGSTORE_CLI_VERSION=v1.3.1
  +ENV BABEL_CLI_VERSION=v7.5.5
  +ENV BABEL_CORE_VERSION=v7.5.5
  +ENV BABEL_PRESET_ENV=v7.5.5
  +ENV BABEL_PRESET_MINIFY_VERSION=v0.5.1
   
   ADD https://nodejs.org/download/release/v${NODEJS_VERSION}/node-v${NODEJS_VERSION}-linux-x64.tar.gz /tmp
   RUN tar -xzf /tmp/node-v${NODEJS_VERSION}-linux-x64.tar.gz --strip-components=1 -C /usr/local
  
positive.code: RUN tar -xzf /tmp/node-v${NODEJS_VERSION}-headers.tar.gz --strip-components=1 -C /usr/local
  
  RUN npm init -y
  RUN npm install --production -g \
      sass \
      sass-lint \
      typescript \
      tslint \
      markdown-spellcheck \
      svgstore-cli \
      svgo
  RUN npm install --production --save-dev @babel/core @babel/cli @babel/preset-env
  RUN npm install --production --save-dev babel-preset-minify
  RUN npm install --production --save @babel/polyfill
  
  #############
  # Ruby
  
negative.code: # Copyright 2019 Istio Authors
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  # This is used to build Istio's primary build container, which contains all the tools
  # necessary to perform and all build activities in all Istio repos.
  #
  # The container is built using different contexts, one per execution environment (plain binaries, Ruby, nodejs), and
  # then combined into the final image.
  #
  # We pin versions of stuff we install. Modify the various XXX_VERSION variables within the indivudual build contexts
  # in order to control these versions.
  #
  # NOTE: This is still a work-in-progress and only some Istio repos use this. More tools will be
  # added here as we onboard more repos.
  
  #############
  # Binary tools
  #############
  
  FROM golang:1.12.5 as binary_tools_context
  
  # Pinned versions of stuff we pull in
  ENV PROTOBUF_VERSION=3.6.1
  