anchor.diff:                            libffi-dev \
                             libssl-dev \
                             libtool \
  +                          libxml2 \
  +                          libxml2-dev \
  +                          libxslt1.1 \
  +                          libxslt1-dev \
                             python \
                             python-dev \
                             vim-tiny \
  
positive.code:                           libwebp-dev \
                            zlib1g \
                            zlib1g-dev \
      && mkdir libxml2 \
          && curl -sSL ftp://xmlsoft.org/libxml2/libxml2-2.9.2.tar.gz | tar xz --strip 1 -C libxml2 \
          && cd libxml2 \
          && ./configure --prefix=/usr \
          && make \
          && make install \
          && ldconfig \
          && cd .. \
          && rm -rf libxml2 \
      && mkdir libxslt \
          && curl -sSL https://git.gnome.org/browse/libxslt/snapshot/libxslt-1.1.28.tar.xz | tar xJ --strip 1 -C libxslt \
          && cd libxslt \
          && ./autogen.sh --prefix=/usr \
          && make \
          && make install \
          && ldconfig \
          && cd .. \
          && rm -rf libxslt \
      && curl -sSL https://bootstrap.pypa.io/get-pip.py | python \
      && pip install git+https://github.com/scrapy/scrapy.git \
                     git+https://github.com/scrapy/scrapyd.git \
  
negative.code:                                       libffi-dev \
                                        libssl-dev \
                                        libtool \
                                        libxml2-dev \
                                        libxslt1-dev \
                                        python-dev \
      && apt-get purge -y --auto-remove libtiff5-dev \
                                        libfreetype6-dev \
  