anchor.diff:  RUN mkdir /build
   WORKDIR /build
   ADD ./hackage-server.cabal ./hackage-server.cabal
  -RUN cabal sandbox init
  +RUN cabal v1-sandbox init
   # TODO: Switch to Nix-style cabal new-install
  -RUN cabal install --only-dependencies --enable-tests -j --force-reinstalls
  +RUN cabal v1-install --only-dependencies --enable-tests -j --force-reinstalls
   ENV PATH /build/.cabal-sandbox/bin:$PATH
   
   # needed for creating TUF keys
  -RUN cabal install hackage-repo-tool
  +RUN cabal v1-install hackage-repo-tool
   
   # add code
   # note: this must come after installing the dependencies, such that
  
positive.code: 
  # Dependencies
  RUN DEBIAN_FRONTEND=noninteractive apt-get install -y unzip libicu-dev postfix
  RUN DEBIAN_FRONTEND=noninteractive apt-get install -y ghc-8.2.2 cabal-install-2.0
  ENV PATH /opt/ghc/bin:$PATH
  RUN cabal update
  
  # Required Header files
  RUN apt-get install -y zlib1g-dev libssl-dev
  
negative.code: RUN hackage-repo-tool create-mirrors --keys keys -o datafiles/TUF/mirrors.json
  
  # build & test & install hackage
  RUN cabal v1-configure -f-build-hackage-mirror --enable-tests
  RUN cabal v1-build
  # tests currently don't pass: the hackage-security work introduced some
  # backup/restore errors (though they look harmless)
  # see https://github.com/haskell/hackage-server/issues/425
  # RUN cabal v1-test
  RUN cabal v1-copy && cabal v1-register
  
  # setup server runtime environment
  RUN mkdir /runtime
  