anchor.diff:  
   RUN ACLOCAL_PATH="/usr/local/share/aclocal" && \
       export ACLOCAL_PATH && \
  -	curl -o /root/libsigcplusplus.tar.gz -SL https://github.com/GNOME/libsigcplusplus/archive/${SIGC}.tar.gz && \
  +    curl -o /root/libsigcplusplus.tar.gz -SL https://github.com/GNOME/libsigcplusplus/archive/${SIGC}.tar.gz && \
       cd /root && \
       tar -zxvf libsigcplusplus.tar.gz && \
       cd libsigcplusplus-${SIGC} && \
  
positive.code:   libgstreamer1.0-dev \
    libgstreamer-plugins-base1.0-dev \
    libgstreamer-plugins-bad1.0-dev \
    libwebkitgtk-3.0-dev \
    libboost-filesystem1.58-dev \
    libboost-program-options1.58-dev \
    gstreamer1.0-tools \
    mesa-common-dev \
    libgl1-mesa-dev \
  
negative.code:     rm cmake.tar.gz
  
  RUN curl -o /root/gtest.tar.gz https://codeload.github.com/google/googletest/tar.gz/release-${GTEST} && \
      cd /root && \
      tar -zxvf gtest.tar.gz && \
      cd googletest-release-${GTEST} && \
      cmake . && \
  