Py.test -n => "py.test: Error: Unrecognized Arguments: -n"

I am trying to distribute django tests to multiple processes to speed up test runs. I am using py.test in a virtual environment. My relevant versions are: $ pip freeze | grep test

Solution 1:

Figured out it was:

-p no:xdist 

in the addopts section in tox.ini. Removed it and xdist worked.