-RUN cd /tmp/arvados-python-client-* && $pythoncmd setup.py install
-RUN if test -d /tmp/schema-salad-* ; then cd /tmp/schema-salad-* && $pythoncmd setup.py install ; fi
-RUN if test -d /tmp/cwltool-* ; then cd /tmp/cwltool-* && $pythoncmd setup.py install ; fi
-RUN cd /tmp/arvados-cwl-runner-* && $pythoncmd setup.py install
+RUN $pipcmd install wheel
+RUN cd /tmp/arvados-python-client-* && $pipcmd install .
+RUN if test -d /tmp/schema-salad-* ; then cd /tmp/schema-salad-* && $pipcmd install . ; fi
+RUN if test -d /tmp/cwltool-* ; then cd /tmp/cwltool-* && $pipcmd install . ; fi
+RUN cd /tmp/arvados-cwl-runner-* && $pipcmd install .
+
+# Sometimes Python dependencies install successfully but don't
+# actually work. So run arvados-cwl-runner here to catch fun
+# dependency errors like pkg_resources.DistributionNotFound.
+RUN arvados-cwl-runner --version