anchor.diff:          && rm -rf /var/lib/apt/lists/*
   
   #install fake X server
  -RUN wget http://ftp.us.debian.org/debian/pool/main/x/xorg-server/xvfb_1.17.3-2_amd64.deb
  +RUN wget http://ftp.us.debian.org/debian/pool/main/x/xorg-server/xvfb_1.18.1-1_amd64.deb
   RUN wget http://ftp.us.debian.org/debian/pool/main/libx/libxfont/libxfont1_1.5.1-1_amd64.deb
   RUN wget http://ftp.us.debian.org/debian/pool/main/libf/libfontenc/libfontenc1_1.1.2-1+b2_amd64.deb
   RUN wget http://ftp.us.debian.org/debian/pool/main/x/xkeyboard-config/xkb-data_2.12-1_all.deb
  
positive.code: RUN wget http://ftp.us.debian.org/debian/pool/main/libx/libxaw/libxaw7_1.0.13-1_amd64.deb
  RUN wget http://ftp.us.debian.org/debian/pool/main/libx/libxkbfile/libxkbfile1_1.0.8-1_amd64.deb
  RUN wget http://ftp.us.debian.org/debian/pool/main/x/x11-xkb-utils/x11-xkb-utils_7.7+2_amd64.deb
  RUN wget http://ftp.us.debian.org/debian/pool/main/x/xorg-server/xserver-common_1.17.3-2_all.deb
  RUN dpkg -i libfontenc1_1.1.2-1+b2_amd64.deb
  RUN dpkg -i libxfont1_1.5.1-1_amd64.deb
  RUN dpkg -i xkb-data_2.12-1_all.deb
  
negative.code:                 patch \
                  xz-utils \
                  zlib1g-dev \
                  build-essential \
                  git \
  		libasound2 \
   		python-ply \
  