For some of the tests a local toxiproxy installation is needed.
Unfortunately the docker version of toxiproxy does not work correctly on mac. It would need --net=host which does not work on mac as docker is run in a vm. So currently you need to install toxiproxy using brew manually and start it before the tests.
If toxiproxy is not present the respective tests will be skipped with a message that toxiproxy server is missing. Because of a bug in pax exam the tests simply succeed. So be aware that they might not check anything.