anchor.diff:  
   # Build aufs tools, do this here as they need kernel headers and to match aufs
   # Fortunately they are built statically linked
  -
  -# aufs-util 20151116
  -ENV AUFS_TOOLS_REPO https://github.com/Distrotech/aufs-util.git
  -ENV AUFS_TOOLS_COMMIT b5e7e204036da5e815ddec15a847a03c232771b4
  -
  -RUN git clone ${AUFS_TOOLS_REPO} && \
  -    cd /aufs-util && \
  -    git checkout "$AUFS_TOOLS_COMMIT" && \
  +RUN cd /aufs-util && \
       CPPFLAGS="-I/tmp/kernel-headers/include" CFLAGS=$CPPFLAGS LDFLAGS=$CPPFLAGS make && \
       DESTDIR=/tmp/aufs-utils make install && \
       rm -rf /tmp/aufs-utils/usr/lib /tmp/aufs-utils/usr/share && \
  
positive.code: 
  COPY kernel_config /linux/arch/x86/configs/x86_64_defconfig
  COPY kernel_config.debug /linux/debug_config
  
  RUN if [ $DEBUG -ne "0" ]; then \
      cat /linux/debug_config >> /linux/arch/x86/configs/x86_64_defconfig; \
  
negative.code: FROM mobylinux/debian-build-kernel:a009a11bf0ad
  
  ARG KERNEL_VERSION=4.4.20
  
  ENV KERNEL_SOURCE=https://www.kernel.org/pub/linux/kernel/v4.x/linux-${KERNEL_VERSION}.tar.xz
  
  