+ python3-arvados-cwl-runner=$cwl_runner_version
+
+# use the Python executable from the python-arvados-cwl-runner package
+RUN rm -f /usr/bin/python && ln -s /usr/share/python2.7/dist/python-arvados-python-client/bin/python /usr/bin/python
+RUN rm -f /usr/bin/python3 && ln -s /usr/share/python3/dist/python3-arvados-cwl-runner/bin/python /usr/bin/python3