Oh, I don't know that.
but flake8 uses either `setup.cfg` or `tox.ini` which is found first.
So `findfile()` does not work fine in this case.

For example, there are some project files:

- root/setup.cfg
- root/foo/tox.ini
- root/foo/bar/baz.py

Running flake8 to `root/foo/bar/baz.py`, then flake8 uses `root/foo/tox.ini`. because it is nearby `root/foo/bar/baz.py`.