def in_venv_world_fixture(self, venv_world: Path) -> Iterator[None]:
        """For running tests inside venv_world, and cleaning up made files."""
        with change_dir(venv_world):
            self.make_file("myproduct.py", """\
                import colorsys
                import third
                import nspkg.fifth
                import nspkg.sixth
                print(third.third(11))
                print(nspkg.fifth.fifth(22))
                print(nspkg.sixth.sixth(33))
                print(sum(colorsys.rgb_to_hls(1, 0, 0)))
                """)

            self.del_environ("COVERAGE_TESTING")    # To get realistic behavior
            self.set_environ("COVERAGE_DEBUG_FILE", "debug_out.txt")
            self.set_environ("COVERAGE_DEBUG", "trace")

            yield

            for fname in os.listdir("."):
                if fname not in {"venv", "another_pkg", "bug888"}:
                    os.remove(fname)
For running tests inside venv_world, and cleaning up made files.
tests/test_venv.py