I use catkin as build system for a package using Python 3. So far this has not been a problem as our code does not really use ROS at all (except from catkin).

Now I added Python unit tests using the following structure:

#!/usr/bin/env python3
import unittest

class TestFoobar(unittest.TestCase):

    def test_foo(self):
        ...

if __name__ == "__main__":
    import rosunit
    rosunit.unitrun("my_package", 'test_foobar', TestFoobar)

When I execute the test directly (e.g. via rosrun my_package test_foobar.py), the test is running with Python 3 and all is good. However, when running catkin run_tests, the shebang seems to be ignored and the test is executed with Python 2 (which fails due to incompatibilities).

Unfortunately, I'm still stuck with ROS Kinetic on Ubuntu 16.04.

So the actual question: Is there a way with Kinetic to make the tests being executed with Python 3?

I already tried adding -DPYTHON_EXECUTABLE=/usr/bin/python3 which works for building but does not seem to have an effect on the test.