in noxfile.py [0:0]
def cover(session):
"""Run the final coverage report.
This outputs the coverage report aggregating coverage from the unit
test runs (not system test runs), and then erases coverage data.
"""
session.install("coverage", "pytest-cov")
session.run("coverage", "report", "--show-missing", "--fail-under=0")
session.run("coverage", "erase")