anchor.diff:  RUN \
       pip instal virtualenvwrapper && \
       source /usr/local/bin/virtualenvwrapper.sh && \
  -    mkvirtualenv -p /usr/bin/python3 pytre && \
  +    mkvirtualenv --no-site-packages -p /usr/bin/python3 $PYENV_NAME && \
       pip install -r root/pypes_requirements.txt
   
   ENV WORKON_HOME $HOME/pyenvs
  
positive.code: ENV PETPVC_GIT https://github.com/UCL/PETPVC.git
  ENV CAMINO_GIT git://git.code.sf.net/p/camino/code
  ENV ANTS_GIT https://github.com/stnava/ANTs.git
  
  
  # Install.
  RUN \
  
negative.code: RUN \
      mkdir ants && \
      cd ants && \
      git clone $ANTS_GIT -b $ANTS_VERSION ANTs && \
      cd ANTs && \
      git am --signoff < /root/patches/ANTs/0001-fix-ifstream-error.patch && \
      cd .. && \
      mkdir build && \
      cd build && \
      cmake -DUSE_VTK=ON \
  