Was unable to get it to work with Python 3

[bout10bucks]

$ rivalctl --cpi2 2000
Traceback (most recent call last):
File "/usr/bin/rivalctl", line 9, in
load_entry_point('rivalctl==0.1', 'console_scripts', 'rivalctl')()
File "/usr/lib/python3.4/site-packages/rivalctl-0.1-py3.4.egg/rival/rivalctl.py", line 67, in main
_main(args)
File "/usr/lib/python3.4/site-packages/rivalctl-0.1-py3.4.egg/rival/rivalctl.py", line 42, in _main
reports.append(set_cpi_2(args.cpi2))
NameError: name 'set_cpi_2' is not defined

[nixi-awoo]

It has to be installed using Python 2 (for me at least).

sudo python2 setup.py install

You will, of course, need all of the dependencies for Python2.
Also make sure you run the rivalctl command with sudo.

There is a nice package in the AUR in case you are running Arch or any Arch-based distribution.
https://aur.archlinux.org/packages/rivalctl-git/