Through `coverage.py`. This saves the user from all the required env
setup required for `coverage.py` to successfully generate the report
afterwards. Instead all of this is taken care automatically, by just
running:
./scripts/coverage.py --run ./build/coverage/.../mytest arg1 ... argN
`coverage.py` takes care of running the test and generating a coverage
report from it.
As a side effect, also fix `main()` ignoring its `argv` parameter.