anchor.diff:      wget -P tarballs https://github.com/phracker/MacOSX-SDKs/releases/download/${SDK_VERSION}/MacOSX${SDK_VERSION}.sdk.tar.xz && \
       ./build.sh &&                                             \
       osxcross-macports install                                 \
  -	lua50                                                 \
   	lua51                                                 \
   	lua52                                                 \
  +	lua                                                   \
   	openjdk8                                              \
   	python27                                              \
   	python35                                              \
  
positive.code: 	ruby25                                                \
  	ruby26
  
  # Run environment.
  CMD /bin/bash
  
negative.code: 
  # Install macosx build tools (osxcross) and libraries (macports).
  ENV PATH /opt/osxcross/target/bin:${PATH}
  RUN export SDK_VERSION=10.13 &&                               \
      export MACOSX_DEPLOYMENT_TARGET=${SDK_VERSION} &&         \
      export UNATTENDED=1 &&                                    \
  