anchor.diff:  
   ################################################################################
   # PACKAGES
  +#
  +# Add commands required for building images.
  +# To minimize rebuilds, binaries that are modified less often
  +# should be in earlier RUN commands.
   ################################################################################
   
  -# Add commands required for building images.
   COPY core/build /package/airstack-0.1.0/build
   RUN set -e; \
     ln -s /package/airstack-0.1.0 /package/airstack; \
  
positive.code: # Packages::dropbear
  RUN /command/core-package-install dropbear
  
  # Packages::haproxy
  RUN /command/core-package-install haproxy
  
  # Packages::serf
  RUN /command/core-slashpackage-install serf-0.6.3
  
  # Packages::Lua
  RUN set -e; \
    /command/core-package-install luajit luarocks; \
    luarocks install --server=http://rocks.moonscript.org luaposix; \
    ln -s /package/airstack/core/lua/airstack.lua /usr/local/lib/lua/5.1/airstack.lua
  
  # Packages::test
  RUN luarocks install --server=http://rocks.moonscript.org busted
  
  
  ################################################################################
  
negative.code: ################################################################################
  
  FROM debian:jessie
  USER root
  ENV HOME /root
  WORKDIR /root
  