[Django]-Jenkins not failing on tests that fail in coverage

I am hitting the same issue. My Jenkins build always passes even if Coverage.py has some failing tests (I use the same command as you).

I have come up with a workaround but would ideally like to know if you figured it out?

My workaround uses the TextFinder plugin and I search the console for a specific string which I then fail the build if found….Hack-y I know!

https://wiki.jenkins-ci.org/display/JENKINS/Text-finder+Plugin