anchor.diff:        --enable-debug \
         --enable-lld \
         --enable-lldb \
  -      --enable-optimize
  +      --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
  
positive.code: FROM ubuntu:16.04
  
  RUN apt-get update && apt-get install -y --no-install-recommends \
    g++ \
  
negative.code:   cmake \
    sudo \
    gdb \
    xz-utils \
    lld \
    clang
  
  COPY scripts/sccache.sh /scripts/
  RUN sh /scripts/sccache.sh
  