pytest-xdist: pytest-xdist hangs if max-slave-restart is set and the restart limit is reached

It can be observed in this build: https://travis-ci.org/ClearcodeHQ/pytest-dbfixtures/jobs/108118580

I’m testing if a package is configured properly (all non py files are included, hence change to install) and installing the package with “pip install .” before the test. pytest_load_initial_conftests throws a ValidationError if the additional files can not be accessed. however I end up with a loop of restarting slaves indefinitely, or if I set --max-slave-restart, I end up with hanging py.test as well.