It seems system packages can't be found when using "3.4_with_system_site_packages" python. Possibly related to https://github.com/travis-ci/travis-ci/issues/8048
@@ -1,5 +1,7 @@
# Use trusty for newer graphviz
sudo: required
+# https://blog.travis-ci.com/2017-06-21-trusty-updates-2017-Q2-launch
+group: deprecated-2017Q2
dist: trusty
language: python