Combine output from py.test and boost unit_test for Jenkins/xunit with CTest

I have a CMake environment with CTest which currently generates a boost/unit_test binary and like described here it's being called like this:

test_exe --log_format=XML --log_sink=results.xml

to generate output which can be handled by the Jenkins' xUnit-plugin.

I now want to integrate add Python tests using py.test and of course I want to have detailed test results on the Jenkins dashboard, too.

This post suggests it's possible to provide Jenkins with more than one result files which would currently my strategy.

But since I'm using CTest - isn't there a way to let CTest interpret nested test results? What if I'm having separate tests without boost/unit_test which I had to run via ctest -T Test to get output Jenkins can handle?

What's the recommended way to configure such a test environment?