anchor.diff: -FROM ubuntu:16.04
  +FROM ubuntu:18.10
   
   RUN apt-get update && apt-get install -y --no-install-recommends \
     g++ \
  
positive.code:   cmake \
    sudo \
    gdb \
    xz-utils
  
  COPY scripts/sccache.sh /scripts/
  RUN sh /scripts/sccache.sh
  
negative.code:       --enable-debug \
        --enable-lld \
        --enable-lldb \
        --enable-optimize \
        --set target.x86_64-unknown-linux-gnu.linker=clang \
        --set target.x86_64-unknown-linux-gnu.cc=clang \
        --set target.x86_64-unknown-linux-gnu.cxx=clang++
  
  ENV SCRIPT \
    python2.7 ../x.py build && \
    python2.7 ../x.py test src/test/run-make-fulldeps --test-args clang
  